Analytic
Analytic
d= √ ¿ ¿
1
A=
2
[ ( X 1 Y 2+ X 2 Y 3+ … X n Y 1 )−( Y 1 X 2 +Y 2 X 3 +… Y n X 1 ) ]
Sample Problem
Find the area of polygon joining the points (3, 0), (2, 3), (-1, 2), (-2, -1) and (0, 2).
Solution:
Note: The points are given already in the counterclockwise orientation
Thus:
A=
[
1 3 2 −1 −2 0 3
2 0 3 2 −1 −2 0 ]
A - 1/2 [(9 +4+ 1+4+ 0) - (0 - 3 - 4 - 0 - 6)]
A = 3 1/2 square units
Division of Line Segment
Let P (x, y) be a point on the line joining P1 (Xl, Yl) and P2 (X2, Y2) and located in such a way that segment P1 P is a
given fraction k P1P2, that is P1 P = P1P2.
x = x1 + k (x2 - x1)
Y = Yl + k (Y2 -Yl)
5. The directed segment A1A2 is the projection of the segment P1P2 on the x-axis
6. The directed segment B1B2 is the projection of the segment P1P2 on the y-axis
Obviously, A1A2 = x2 - x1
B1B2 = y2 - yl
Sample problem:
Given two points P1 (2, -1) and P2(6, 5), find the projections of P1P2 on the x and y axis
Solution:
a) Projection on x-axis = x2 - x1
= 6-2 =4
b) Projection on y-axis = y2 - yl
= 5-(-1) =6
Slope, Parallel and Perpendicular Lines
Line L
Definition
1. The inclination (θ ) of a line L is defined as the least positive angle made by the line with the positive x-axis.
2. The slope (m) of a line L is defined as the tangent of its inclination,
rise y 2− y 1
m=tan θ m= =
run x 2−x 1
Condition for Parallel
1. Two lines L1 and L2 are perpendicular if their slopes are equal (ml = m2)
2. Condition for Perpendicularity
Two lines L1 and L2 are perpendicular with each other if the slope of one equal to the negative reciprocal of the
slope of the other
−1
m 1= ∨m1 m2=−1
m2
Notes:
1. If the Line is inclined to the left, 90o< θ <180o and m < 0.
2. If the line L is inclined to the right, 0 < θ < 90o and m > 0
θ=β -α ; m1 = tan
α
y
tan θ = tan ( β - α )
tan β−tan α
tan θ= m2=tan β
1+ tan β−tan α
m2−m1
tanθ=
1+ m1 m2
Sample Problem:
Given three points A (-1, 1), B (5, -1), C (4, 3), find the angle made by segments AB and AC.
Solution:
First, find the slope of AB and AC
−1−1 −1 3−1 2
m AB= = ; m AC = =
5+1 3 4+ 1 5
2 1
+
m2−m1 5 3
tanθ=¿ = ¿
1+ m1 m2
1−
2 1
5 3 ()
11
tanθ=
13
−1 11
θ=tan , θ=40.236 ° Answer
13
Locus - the curve traced by an arbitrary point as it moves in a plane is called locus of a point
- the locus of an equation is a curve containing only those points whose coordinates satisfy the equation.
By similarity of triangles
y 2− y 1
y− y 1= ( x−x 1 ¿
x2− x1
2. Point-slope Form y
y 2− y 1
ln (1) replacing by m,
x 2−x 1
y− y 1=m(x−x 1)
m=tan θ
0 ° ≤θ ≤ 180 °
3. Slope-Intercept Form
y=mx+b
where m = slope
b= y intercept
4. Two-Intercept Form
x y
+ =1
a b
Where: a = x intercept
b = y intercept
x cosθ +ysinθ = ρ
Reduction to Normal Form:
Given the line Ax + By + C = 0
Note: The sign of the radicand must be chosen such that the last term will become negative since ρ>0
Sample Problems:
1. Find the equation of a line passing through (-1, -3) and (2, 4)
Solution:
y 2− y 1
Using two-point form formula: y− y 1= ¿
x2− x1
Where x 1=−1 x2 =2
y 1=−3 y 2=4
4+3
y +3= ( x +1)
2+1
Simplifying, 7 x−3 y−¿ 2=0 Answer
2. Find the equation of the line having a slope of 1/3 and passing through the point (5, 1).
Solution:
Using the point-slope form: y – y 1=m ( x−x 1 )
1
Where, x 1=5 , y 1=1 , m=
3
1
y−1= (x−5)
3
Simplifying, x- 3y -2 = 0 Answer
5. Find the equation of a line passing through (2, -1) and parallel to the line 12x - 4y + 5 = 0 Solution:
Since the required line is parallel to the given line their slopes are equal
12 5
For the given line, 12x – 4y + 5 = 0 or y= x+
4 4
Here slope m = 3
Using the same slope m = 3
y− y 1=m ( x−x 1 ) where x 1=2 y 1=−1 m=3
y +1=3 ( x−2 )
Simplifying, 3x – y – 7 = 0 Answer
6. Find the equation of a line having normal angle = 60 0 and normal length 1
Solution:
Normal form: x cos θ+ y sin θ= ρ
Where θ=60 ° , ρ=1
x cos θ+ y sin θ=1
Simplifying, x+
1 √ 3 y=1
2 2
x + √ 3 y −2=0 Answer
Sample Problems:
d = 2 units (the point (3, - 1) and the origin are on the opposite side of the line)
The directed distance from a point P( x o , y o) to a line Ax +By + C = 0 is given by the formula:
where the sign of the radical is same as sign of B (or C when B = 0) so that,
Remarks:
1. if d > 0, the origin and P lie on opposite sides of the given line
2. if d < 0, the origin and P lie on the same side of the line
Notes:
Regardless of the location of the point Po ( x o , y o), the distance being always positive the formula can be expressed using
the absolute value as:
| Ax o +By 0 +C|
d=
√ A2 + B2
Line Through the Intersection of Two Lines
Let Ax + By + C = 0and
Dx + Ey + F = 0 be two intersecting lines, where A, B, C, D, E and F are constant and
A = B = C = D = E = F≠ 0
The equation of the family of lines passing through the intersection of the two given lines is given by,
(Ax + By + C) +k (Dx + Ey + F) = 0
Where k is an arbitrary constant
Sample Problem:
1. Find the equation of the line passing through the intersection of the lines x - y + 5 = 0 and x +
5y – 4 = 0 and passing through the point (1, 0).
Solution:
The equation of the family is (x - y + 5) + k (x + 5y - 4) = 0
Since the required line is a member of the family, substitute the point (1, 0) in the locus of the family and then solve
for k
[(l) - 0 + 5] + k [l + 5(0) -4] = 0
6 – 3k = 0, k = 2
Substituting k in the equation of the family of lines above,
(x – y + 5) + 2 (x +5y – 4) = 0
Simplifying, 3x + 9y - 3= 0
x + 3y – 1 = 0 Answer
INTERCEPT OF A CURVE
x- intercept - directed distance from the origin to the point where the curve crosses the x-axis
To find the x intercept of a curve, set y = 0, then solve for x.
y - intercept - the directed distance from the origin to the point where the curve crosses the y- axis. To find the y intercept
of a curve, set x = 0, then solve for y symmetry
1. if the equation of a curve does not change upon replacement of y by - y, then the locus is symmetric with respect to
the x-axis
f (x, - y) = f (x,y) = 0
2. if an equation of a curve does not change upon replacement of x by - x, then the locus is symmetric with respect
to the y-axis
f (-x, y) = f (x, y) = 0
3. if an equation of a curve does not change upon replacement of x by - x and y by - y, then the locus is symmetric
with respect to the origin.
f (- x, - y) = f (x, y) = 0
ASYMPTOTE - a straight line which the curve f(x, y) = 0 approaches indefinitely near as its tracing point approaches
to infinity.
4. To find the vertical asymptote, solve the equation for y in terms of x and set the linear factors of the denominator
equal to zero.
5. To find the horizontal asymptote, solve the equation for x in terms of y and set the linear factors of the
denominator equal to zero.
CIRCLE
Circle is the locus of a point which moves so that it is always equidistant from a point
Note: fixed point is called the center & fixed distance is called the radius
Equation of a Circle
A. In normal form
Consider a circle of radius r with center at C (h, k)
Let P(x, y) be a point in the circle
By Pythagorean Theorem
¿ STANDARD FORM
Sample Problems:
1. Find the center and radius of circle x2 + y2 + 8x - 10y + 32 = 0
Solution:
Reduce the given equation to standard form by completing the square in x and y:
(x2 + 8x + 16) + (y2 – 10y + 25) = - 32 + 16 +25
(x + 4)2 + (y – 5)2 = 9↔ (x – h)2 + (y – k)2 = r2
Here, C (h, k) = (-4, 5); r = 3
2. Find the equation of the circle passing through the points of intersection of the circles x 2 + y 2 = 16 and
x 2 + y 2 – 10y = 0 and passing through the point (1, 0).
Solution:
The equation of the family is
x 2 + y2 - 25 + k (x 2 + y 2 - 10y) = 0
To determine the particular members of the family,
Solve for k by substituting the coordinates of the point (1, 0),
1+0 – 25 + k (1 + 0 – 0) = 0
k = 24
Substituting k in the equation of the family of circles,
x 2 + y2 - 25 + k (x 2 + y 2 - 10y) = 0
25x2 + 25y 2 - 240y - 25 = 0
Simplifying, 5x2 + 5y2 - 48y – 5 = 0 Answer
PARABOLA
The locus of a point that moves in a plane such that its distance from a fixed point equals its distance from a
fixed line.
1. Fixed point is called focus 2. 2. Fixed line is called
directrix
3. Axis - the line passing through the focus and perpendicular to the directrix
4. Vertex - The midpoint of the segment of the axis from the focus to the directrix.
5. Latus rectum - a segment passing through the focus and perpendicular to the axis of the parabola.
6. Focal distance - distance from vertex to focus = a
Remarks:
1. The vertex and focus always lie on the axis of the parabola.
2. Focus is always located on the concave side of the parabola.
1. Vertical Axis
Ax2 + Dx + Ey + F = 0, E or A must not be zero
2. Horizontal Axis
Cy2 + Dx + Ey + F = 0, D or C must not be zero
Sample Problems:
1. Find the vertex, focus, equation of the axis, equation of directrix and the ends of the latus rectum of the parabola (x
2
- 2x+1 = 0) and 8y + 15 +1= 0.
Solution:
Since the given equation is linear in y, the parabola has vertical axis.
By completing the square:
(x 2 - 2x + l) = 8y+15 +1=0
(x – 1)2 = 8(y + 2) --- concave upward
a.) Vertex: V (h, k); V (l, - 2)
b.) Focus: F (h, k + a)
Here 4a = 8, a = 2
c.) Equation of Axis:
x = h: x = 1
d.) Equation of Directrix
y = k – a; y = - 4
e.) Ends of Latus Rectum
L (h – 2a, k + a); L (-3, 0)
R (h + 2a, k + a); R (5, 0)
2. A parabolic arc has a height of 20 ft. and a width of 36 ft. at the base. If the vertex of the parabola is at the top of the
arc at, what height above the base is it 18 ft. wide?
Solution:
2
= where b = 18 h1 =?
B h2
b = 36 h2 = 20
Substituting
18 h1
2
2
= ; h1 = 5
32 20
Now, h = 20 – h1 = 20 - 5
h = 15 feet Answer
ELLIPSE
Ellipse is the locus of a point P (x, y) in a plane which that the sum of its distances from two fixed points is
constant.
Notes:
1. The two fixed points are called foci
2. Major axis - the segment cut by the ellipse on the line containing the foci a segment joining the two vertices of
an ellipse of length equal to 12al
3. Diameters - the chords of an ellipse that pass through the center
4. Vertices - the endpoints of the diameter through the foci the endpoints of the major axis
5. Latus Rectum - the segment cut by the ellipse passing through the foci and perpendicular to the major axis
6. Eccentricity - measure the degree of flatness of an ellipse
General Remarks
1. Vertices and foci lie on the major axis
2. |a| is the distance from the center to the vertex
3. |c| is the distance from the center to the foci (focal distance)
4. The ellipse is symmetrical to the major, minor axes and the center
Important Relations
1. a > b, a > c
2. a2 = b2 + c2
3. e = eccentricity = c/a < 1
4. Latus Rectum, LR = 2b 2 /a
Sample Problems
HYPERBOLA
Hyperbola is the locus of point P (x, y) in a plane which moves such that the difference of its distances from two
fixed points is a positive constant.
Notes:
1. The two fixed points are called foci
2. Transverse axis - a line segment joining the two vertices of hyperbola
3. The length of the transverse axis is |2a|
4. Conjugate Axis - the perpendicular bisector of the transverse axis
5. The length of the conjugate axis is |2b|
6. Center - point of intersection of transverse and conjugate axis
7. Central Rectangle - the rectangle whose area is (2a) (2b) and whose diagonals are asymptotes of hyperbola
8. Vertices - the endpoints of the transverse axis
9. Asymptotes of the hyperbola - two intersecting lines containing the diagonal of the central rectangle
10. To find the equation of the asymptote, set the right side of the equation of hyperbola in standard form to zero
then solve for y.
11. Central Circle - the circle of radius c with center at the center of the hyperbola circumscribing the central
rectangle
12. Equilateral Hyperbola - hyperbola whose transverse axis equals its conjugate axis
13. Conjugate Hyperbolas - hyperbolas whose transverse axis of one is the conjugate axis of the other
Standard Equations of Hyperbola
A. Center at C (h, k), Horizontal Transverse Axis
¿¿
Notes:
Transverse
x
5. Foci: F1(-c, 0)
F2(c, 0)
6. Asymptotes: y = ±b/a x
General Relations
l. c > a, c > b (a = b or a < b or a > b)
If a = b, then the hyperbola is called equilateral hyperbola
2. c2 = a2 + b2
3. Length of Latus Rectum = 2b2 /a
4. Eccentricity, e = c/a > 1
Sample Problem:
1. Find the equation of the hyperbola, center (2,0) focus (2,3) eccentricity = √ 3
Solution:
Since the center and focus have the same abscissas the axis of hyperbola is vertical
c
e= = √3 ; √ 3 a
a
C=3–0=3 focal distances
Solving for a:
From c 2 = a2 + b2 ; b 2=c 2−a 2
2 2
b =c −¿
2
b =9−3=6
Equation: ¿¿
¿¿
2. If the Cutting plane is perpendicular to the axis of the cone, the section is a circle.
3. If the cutting plane is making an angle (other than 90 0) with the axis of the cone, the section is an eclipse
4. If the cutting plane is parallel to one of the elements of a cone, the section is a parabola
5. If the cutting plane is parallel (but not coincident) to the axis of the cone, the section is a hyperbola.
In each of the cases, the cutting plane should not pass through the vertex of the cone, otherwise the section that will be
formed is a degenerate conic.
Degenerate Conic (one point, one line, two lines) is a conic formed if the cutting plane is passing through the vertex
or along one of its elements
Principal Axis of a Conic - is the line through the focus and perpendicular to the directrix
Diameter of a Conic - the locus of the midpoints of a system of parallel chords.
ROTATION OF AXES
Let the x-axis be rotated at an angle θ and let α be the angle formed by Ox' and OP
Consider:
Sample Problem;
That is the point (2, 3) in the new x' - y' system if the x- axis is rotated at an angle 30 o?
Solution:
x = 2, y = 3, θ = 30o
x' = x cos θ + y sin θ = 2 cos 30o + 3 sin 30o = 3.232
y' = - x sinθ + y cosθ = -2 sin 30o + 3 cos θ 30o = 1.598
P' = (3. 232, 1.598) Answer
Notes
1. The equation above represents a parabola, an ellipse, a hyperbola, two straight lines, a point or no locus at all.
2. The cross-product term (xy) can be eliminated upon rotation of axes by an amount of angle θ , expressed as,
A−C
cot 2θ =
B
Sample Problem:
Find the angle of rotation that will eliminate the xy term in the equation 2x 2 + xy + 2y 2 = 1
Solution:
A = 2, B = 1, C = 2
A−C 2−2
cot 2 θ= = =0
B 1
−1
2 θ=cot 0=90 °
θ=45 ° Answer
TRANSLATION OF AXES
Let the origin be shifted to new location at O' (h, k), so that x' and y' are the new coordinate.
Consider
Relations:
x = x' + h or x' = x
–h
y = y' + h or y' = x
–k
Sample Problems:
1. What is the point (4, 5) in the new system if the origin is shifted to the point (-1, 3)
Solution:
x = 4, y = 5, h = 1, k = 3
x' = x – h = 4 – (-1) = 5
y' = y – k = 5 – (-3) = 2
Thus, P' (5, 2) Answer
2. That is the equation 3x - 2y = 5 in the new system if the origin is shifted to the points (5, -1)
Solution:
h = 5, k = 1
x = x' + h = x' + 5
y' = y + k = y' - 1
Substitute x and y in the equation given above
3 (x' + 5) – 2 (y' – 1) = 5
Simplifying
3x' - 2y' = -12 Answer
SUPPLEMENTARY PROBLEMS
1. A point P (x, 3) is equidistant from the points A (l, 5) and B (-l, 2). Find x. Ans. 3/4
2. Find the locus of points P (x, y) such that the distance from P to (3, 0) is twice its distance to (1, 0).
Ans. 3x2 – 3y2 – 2x – 5 = 0
3. Find the length of the segment joining the two midpoints of the sides of the triangle if the length of the third side
opposite to it is 30 cm. Ans. 15 cm
4. A line from, (1, 4) to Q (4, -1) is extended to a point R so that PR = 4PQ. Find the coordinate R. Ans. R (13, -16)
5. Two vertices of a triangle are (0, -8) and (6, 0). If the medians intersect at (9, -3), find the third vertex of the triangle.
Ans. (- 3, - 1)
6. The area of a triangle with vertices (6, 2), (x, 4) and (0, - 4) is 26. Find x. Ans. -2/3 and 50/3
7. Find the length of the median from A of a triangle ABC given vertices A (1, 6), B (- 1, 3) and C (3, -3). Ans. 6
8. If the midpoint of a segment is (5, 2) and one endpoint is (7, -3), what are the coordinates of the other end? Ans. (3, 7)
9. Given vertices of a triangle ABC:
A (l, 5), B (-1, 1) and C (6, 3). Find the intersection of the median. Ans. (2, 3)
10. Find the inclination of the line 2x + 5y = 10. Ans. 158.2o
ELLIPSE SUPPLEMETARY
1. In the ellipse below determine the following: a) Center, b) Vertex, c) Foci, d) Major Axis, e)
Minor Axis, f) Latus Rectum, g) Eccentricity
2. In each of the following find the equation of ellipse satisfying the given conditions
A. center at (0, 0), focus at (±√ 3, 0), and b: 1 Ans: x2 + 4y2 = 4
B. center at (1, 0), focus at (1, √ 3) e: √ 3/2 Ans: 4y2 + y2 = 8x
Focus at (0, -1), (-4, -1), a = √ 6 Ans: x2 + 3y2 + 4x + 6y + 1 = 0
C. center at (-1/2, 2) a = 5/2 b= 2 Ans: 16x2 + 25y2 + 16x + 4 = 100y
D. center at (0, 0), vertex (0, 4) e = 1/2 Ans: 4x2 + 3y2 – 48 = 0
3. A satellite orbits around the earth in an ellipse orbit of eccentrically of 0.80 and semi - major axis length 20, 000 km.
If the center of the earth is at one focus, find the maximum altitude (apogee) of the satellite. Ans: 36, 000 km
4. Find the equation of the locus of a point which moves so that the sum of its distance from (-2, 2) and (1, 2) is 5.
Ans: 16 x2 + 25y2 + 16x – 100y + 4 = 0
5. Find the eccentricity of an ellipse whose major axis is thrice a long as its minor axis Ans:2
√ 2
3
6. That is the quadrilateral formed by joining the foci of an ellipse to the endpoints of the minor axis? Ans: rhombus
7. Find the distance of the point (3, 4) to the foci of the ellipse whose equation 4x 2 + 9y 2 = 36 Ans: 3 ± √ 5
8. An arch in the form of a semi - ellipse has a span at 45 m and its greatest height is 12m. There are two vertical
supports equidistant from each other and the ends of the arc. Find the height of the support. Ans: 8 √ 2m.
9. Determine the locus of a point P (x, y) so that the product of the slopes joining P (x, y) to (3, -2) and (-2, 1) is -6.
Ans: 6x2 + y2 - 6x + y - 20 = 0
10. What is the area of the ellipse whose equation is 25x 2 + 16y 2 = 400 Ans. 20π
1. Find the center, vertices, foci and asymptotes, transverse axis, conjugate axis, latus rectum and eccentricity of
hyperbola below.
a. 9x2 - 16y2 + 18x + 64y = 91
b. 16x2 - 4y2 – 62x + 24y + 92 = 0
c. 25x2 - 16y2 = 400
2. Find the equation of the hyperbola satisfying the conditions given in each case
a. Center (3, -1); vertex (l, -1); focus (0, 1) Ans: 5x2 - 4y2 - 30x - 8y + 21=0
b. vertices at (0, 4) and (4, 4); foci at (5, 4) and (-1, 4)
Ans. 5x2 -4y2 + 32y- 64 = 0
c. Center at (1, 1), vertex (l, 3), eccentricity =2 Ans: x2 - 3y2 - + 10 = 0
d. Directrices: y = ± 4 ; asymptote: y = ± 3/2 x Ans: 9y2 - 324x2 - 208 = 0
e. Asymptotes: 3y=± 4 ; foci (± 6, 0) Ans: 400 x2- 225y2 – 5184 = 0
f. Foci (0, 0), (0, 10); asymptote: x+y=5 Ans: 2x2 - 2y2 + 20y - 25 = 0
g. Asymptote: x+y=1 and x-y=1 and passing through (-3,4) and (5, 6)
Ans. x2- y2-2x – 2 = 0
h. Axes along the coordinate’s axes, passing through (-2 5) Ans: 4y2 - 5x2 = 19
i. Vertices at (0, ±4) passing through (-2, 5) Ans: 4y2 - 9x2 = 64
3. Find the eccentricity of a hyperbola whose transverse axis and conjugate axis are equal in length Ans: e=√ 2
SUPPLEMENTARY PROBLEMS
1. Find the point (5, - 3) in the new system if the origin is shifted to the point (-1, 2). Ans. P'(6, -5)
2. The new point is (6, -2) after the origin is shifted to the point (3, - 2). What is the previous point? Ans. P (9, - 4)
3. What is the circle x 2 + y 2 – 2x - 3 = 0 in the new system if the origin is shifted to (1, 2)? Ans. (x’¿2 + (y’¿2 +4y’ = 0
REVIEW PROBLEMS
1. The Y-axis is also called____.
A. ordinate C. point
B. abscissa D. angle
2. In polar coordinate system, the distance from a point to the pole is known as:
A. Polar angle C x-coordinate
B. Radius vector D. y-coordinate
6.The product of the slopes of the equation of 2 lines is -1. One of the lines is___.
A. Non-intersecting C. Perpendicular
B. Parallel D. Skew
9. Find the point on the line 3x + y +4 = 0 that is equidistant from the points (-5, 6) and (3, 2).
A. (-2,2) C. (-2, -2)
B. (-2,3) D. (2,2)
10. Determine the equation of the line passing through the point (1, 17) and (13, 4).
A. 13x - 12y - 217 = 0 C. 13x+12y – 217 = 0
B. 13x - 12y + 217 = 0 D. 13x+ 12y + 217 = 0
11. Find the equation of the line that passes 3 units from origin and parallel to 3x – 4y + 5 = 0
A. 3x – 4y + 15 = 0 C. 3x – 4y - 8 = 0
B. 3x – 4y + 5 = 0 D. 3x – 4y + 8 = 0
14. Find the area of the triangle formed if the sides are given by the equations: 2x - 3y + 21 = 0, 3x-2y-6 = 0, 2x+3y+9 = 0
A. 75 C. 86
B. 97.5 D. 28/3
15. Find the area of the triangle having the vertices at -4 - i, 1 + 2i, 4-3i.
A. 7 C.10
B. 17 D. 107
16. Find the equation of the line passing 3 units from the origin and parallel to 3x + 4y – 10 = 0
A. 3x + 4y – 5 = 0 C. x - 3y + 15 = 0
B. 4x + 3y + 1 = 0 D. 3x + 4y – 15 = 0
18. What is the equation of the line that passes through (- 3, 5) and is parallel to the line 4x - 2y+2 = 0?
A. 4x-2y + 12 = 0 C. 4x + 2y -11 = 0
B. 2x + y + 10 = 0 D. 2x-y + 11 = 0
19. Find the equation of the circle whose center is at (3, -5) and whose radius is 4.
A. x2 + y2 -6x + 10y +18 = 0 C. x2 + y2 - 6x - 10y +18 = 0
B. x2 + y2 +6x + 10y +18 = 0 D. x2 + y2 + 6x - 10y +18 = 0
23. A circle with center at the origin has a radius of 5. Find the equation of a parabola opening to the right that has its
vertex on the circle and crossing the points of intersection of the circle and y-axis.
A. 5x + 25 = y2 C. 5y + 55 = x2
B. 5x - 25 = y2 D. 5y - 55 = x2
26. An arch is in the form of an inverted parabola and has span of 12 feet at the base and a height of 12 feet. Determine
the equation of parabola and give the vertical clearance 4 feet from the vertical centerline.
A. 7.33 ft C. 5.33 ft
B. 6.00 ft D. 6.67 ft
27. A parabola opening to the right that has its vertex on the circle and crosses the circle of unit radius thru the diameter.
If the center of the circle is at the origin, find the coordinates of the focus of parabola.
A. (1/3, 0) C. (-1/3, 0)
B. (3/4, 0) D. (-3/4, 0)
28. Find the family of parabola with vertex at the origin and focus at the x-axis.
A. Cy = x2 C. Cx = y2
A. y = x + C D. x = y2 + C
2
29. What is the equation of a circle that passes thru the vertex and latus rectum of the
curve y2 = 8x?
A. (x- 4¿2 + y 2 = 20 C. (x- 2¿2 + y 2 = 16
B. (x- 5¿2 + y 2 = 25 D. (x- 3¿2 + y 2 = 17
33. Find the equation of the hyperbola whose asymptotes are y = ± 2x and which passes through (5/2, 3).
A. 3x2 - y2 = 9 C. 4x2 - y2 = 16
B. 5x - y = 25 D. 2x2 - y2 = 4
2 2
35. Find the length of the latus rectum of 9x2 - 4y2 - 36x + 16y = 0
A. 5.433 units C. 9.218 units
B. 6.708 units D. 8.694 units
36. Determine the equation describing the locus of point P (x, y), such that the sum of the distances between P and (- 5, 0)
and between P and (5, 0) is constant at 20 units.
A. (x/10)2 + (y/8.66) 2 = l C. (x/5)2 + (y/10) 2 =1
2 2
B. (x/10) + (y/5) = l D. (x/8.66) 2 + (y/10)2 = 1
37. Given the curve 16x2 + 25y2 - 64x - 50y – 311= 0, determine its center.
A. (1,2) C. (2, -1)
B. (2,1) D. (1, -2)
38. A curve has the equation 16x2 + 9y2 - 32x - 128 = 0. Its eccentricity is:
A. 0.88 C. 0.77
B. 0.66 D. 0.55
39. Given the equation of the curve 9x2 +25y2-144x +200y + 751 = 0. Find the distance between the foci.
A. 6 C. 10
B. 8 D. 12
44. The eccentricity of a given curve is equal to zero, the given curve is:
A. parabola C. hyperbola
B. ellipse D. circle