2017-2-KED-KTED
Section A [ 45 marks]
Answer all questions in this section
1. The function f is defined by
{
4
+ k , x ≤−2
f ( x )= x
¿ ln (x+ 3), x>−2
(a) Find ¿ and ¿ [3 marks]
(b) Find k if lim ¿ x →−2 f (x) exists.
Hence, determine whether f is continuous at x=−2 [3
marks]
2. The parametric equations of a curve are x= +1 and y= −1 . The curve
2
t 4
t
crosses the
2
x -axis at A. Find the equation of the tangent to the curve at a point A.
[7 marks]
3. The equation of two curves are given by y 2=2 x and y = .
2 8
x
(a) Sketch the two curves on the same coordinate axes.
[5 marks]
(b) Find the coordinate of the points of intersection of the two curves.
[3 marks]
(c) Calculate the volume of the solid formed when the region bounded by the
two curves and the line x=4 is revolved through π radians about the x -axis.
[5 marks]
4. Solve the differential equation +(tan x ) y =tan x sec x, with condition y=2 when
dy 3
dx
x= .
π
Express your answer in the form of y=f (x ). [7
3
marks]
5. Show that the first three terms in the Maclaurin Series for sin(sin x ) is
1
[4
3 5
x x
x− + −…
3 10
marks] Hence or otherwise find x−sin ( sin x ) .
lim 3
x →0 x
[3 marks]
6. Use the trapezium rule with five ordinates to find an approximate value for
.
9 x
∫4 9
dx
0
Give your answer correct to one decimal place.
[5 marks]
Section B [15 marks]
Answer one question only in this section
7. The diagram shows the diagram y= .
lnx
x
y
A
0 x
The curve has a stationary points at A.
(a) State the ¿ and lim ¿ x →+∞ . [2 marks]
lnx
x
(b) Find the coordinates of the stationary point, A, of the curve, giving your
answer in exact form.
[3 marks]
Hence , show that x e ≤ e x for all positive values of x . [3
marks]
State the intervals for which
(i)
dy
>0,
dx
2
(ii) [2
dy
<0
marks]
dx
(c) Find the point of inflexion of the curve.
[5 marks]
8. Sketch the graph of y=3 ln x and y=2 x +8−x2 on the same coordinate axes.
Hence, show that the equation 3 ln x + x 2−2 x−8=0 has only one real root.
[5
marks]
Show that the equation
x=1+ √ 9−3 ln x
can be rearranged in the form
3 ln x + x −2 x−8=0 . [2 marks]
2
With x 1=3, without performing the iteration processes, show that the iterative
formula
x n+1=1+ √ 9−3 ln x n
converges to the root. [3
marks]
Hence, estimate the root correct to 3 decimal places.
[5 marks]
“If criticism makes you angry and compliments make you happy, bad company will come
your way and good friends will shy away.” -- Confucianism