67% found this document useful (3 votes)
14K views36 pages

Maths 4 Africa Study Guide

Uploaded by

xphumiey
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF or read online on Scribd
67% found this document useful (3 votes)
14K views36 pages

Maths 4 Africa Study Guide

Uploaded by

xphumiey
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF or read online on Scribd
You are on page 1/ 36
rr + oT, = 8 term | + Two = 100% term; etc. «Ta = the nth term (the general term) TF you know what Tn is, you can Find any term in a pattern (a sequence). Add (or subtract) the same number each time. Eg. -5; 0; 5; 10;.. or: 5; 2 -k -h =—""” er we’ +5 +5 45 -3 -3 -3 Multiply by the same number each time. Eg. 2, 4; & 16 vi #8 |e; or: 2% 9, 3 de ol X =P Xie X wi ol Powered by (3 CamScanner ener eral term (Tn) ji a a stant dif ference ] 10, IS; Constant difference = +3 | 5 4 16; | a Think of squares, cubes or other exponents. How can you use these to write | the original sequence? E.g.: (i Te Ts Te Tn lates 9) 16 You can write each term in the r Bg Be ye pattern (I; 45 9% .) aS @ square, Now find the connection between the number he term and the sequence (V';2° 3°; 4: Tigi 123 Powered by CamScanner Algebraic expressions and Substitution NN 5 2 2x° 5x? + SEY + ~2Y 12+ yay | Variable Constant: Coefficient: Exponent: aletter of the alphabet, & xory (x or y can be anything, Its value can change.) a number that stands by itself, eg. 5 or ~12 (5 will always be 5. Its value cannot change.) the number (and its sign) which you find in Front of a variable (eg, -x?= (x? »> the coefficient of x? in -x? is -1) The exponent of - x? is 2. Powered by CamScanner Yr poor + SKY? +2 og. a+ yrs Like terms: Terms with the same type of variables, eg. Sex? and 2 ( (there is an x? in both) Remember: xy? = yr ary? and yx are therefore like terms too. The order of the letters does not matter. Unlike terms: Terms with different types of variables, eg, Say? and = 2y Remember: 2%07y, 3xy’, - 5% and 2x? are all unlike terms +00. Remember: + You can add or subtract like terms only. ” * Terms are separated by a + oF =. ~ Powered by CamScanner Factorisation « Factorise » write an expression as something x some thing (eg. bracket x bracket) + You can check your answer: Multiply the bracket(s) > you should get the Original tern once again, Type Example /Common factor 2xy + 4x0? | = 2xc(y + 2x0) Difference of xc? - 25y" | | squares (2 terms) = (x - sy)(x + 5y) Trinomial (4 or 5 terms) x? +5x-6 (3 terms) = (x +6) -1) | a —¢ Grouping 2x + 2y-x2-xy ' =an+y)-xlx+y) | j = (x + y(2-x) Z a Powered by CamScanner (a) Gommon factor Always look for a common Factor first, 4axs +2xty = 2x%(2x0 + y) 1, Look for the greatest number that can divide into all terms: 2 2. Look for the letter(s) that appear in all Lerms: x Choose the smallest exponent of this letter (because this power can divide into all terms): x2 = common factor: 2x? 3. What, should you write in the bracket? By what should you multiply 2x? to get the original terms once again? > 20%X2x + y) or go? 2ety) (s+ Be 2a aE st ial Powered by CamScanner 4 pif ference of squares (2 terms) 7 4x? -| / \ [| yx? Vl [| = (2x - 1)(ax +1) | Is there a common factor? No, 2, Number of terms: 2 | Ts this a difference (-) of squares? Check: a) Are both terms perfect squares? Yes. b) Is there a minus (a difference)? Yes. : Difference (-) of squares » This becomes!2 brackets: one with a - and one with a + Write - and + in the brackets straight away. Then fill in the rest. i Powered by CamScanner Pr +6 Standard form: ay 5 exponent, x2 rm (nt able +3) y Ne constant , mitSE'+6 term Js there @ common Factor? No. t "Number of terms: 3 . yas this a trinomial in standard Form (2+! + number)? Yes. 5) Find the Factors: » Write x's in left column (factors of x). . Write factors of +6 in right column (+6 = factors: same signs > both + or both -). « Cross multiply and write answers below. + Add these janswers. Which combination gives middle term (+52)? = -2 y x -3 fae -3x Powered by CamScanner | nN & oa ping (q or 5 terms) : ax - ay +2n-2y \ = aay) + 2224) =(x-y)la+2) _ Is there a common factor? No, not in all terms. , Number of terms: 4 Is there a common factor in 2 of the terms? Group. Form 2 groups so that you can take out a common Factor from each group. a) ax -ay = common factor: a b) jae 2y = common factor: 2 - Take out common factor from each group: = a(x -y) + lx -y) . Now take out the new common Factor (x y) = alse = y) + lary) —— Everything that is left = (a= ya 2) goes into this bracket. Powered by (3 CamScanner Factorisation ee 320y - lay . = Syl? 4) = 3y(x - 2)(x +2) | Is there a common factor? Yes, = common factor: 34 1, Look at the bracket (x*-4). Can you factorise this further? 3, Number of terms in bracket: 2 « both terms in bracket ore perfect, squares « minus (- ) «. This is a difference of squares. + syle? 4) = syle 2)ee +2) Powered by (9 CamScanner Algebraic fractions 2-4 KP +2e-3 Ww —_—a —_—_ Tr jerg ax-ma 3 « first step: factorise (common factor, difference of Sum trinomial, grouping) + see what can cancel out then simplify X-1. 6-2K [ez th 3 + make denominators the same (LCM) . then simplify 178 Powered by (9 CamScanner t | | Equations with x: 5X-6+X=10-2x0 sn-6 +x =10-20 srtxt2e =l0+6 gx =16 x =2 Equations with x2: |. x's to one side 2. Numbers to other side x?-3x=4 x?-3x =4 I. x2-3x-4 =° . (x-4)la+i) =° x-4=0 or xt+l=0 x=4 or xe -l Everything to one side (get 0 on the other side) Factorise Remember: o x anything = 0 «either (x - 4) must be 0 = (o)(x+)=0 or (xc +1) must be 0 > (x-4)lo)=0 Powered by (9 CamScanner aphs (straight lines) Gr Gon of a straight line y =mx+c Standard form How steep the line is (the inclination) - gradient ‘ey-inbercept Where the line cuts (intersects) the y-axis vt J, NB! yis always on top This is the same as: Ax change in x You need 2 points on a graph to work out the gradient (m). vot Powered by CamScanner ie Description ‘Gradient, (m) | Sketch mis 8 + Line lopes: Up (deg) ' : From left {0 right “m>o * « If L walk on the (positive) ‘ graph from left to . d eg yea nig, wo Ae nctencest . Graph is iscend y increases too. (increasing). mis — « Line slopes down (Fall) from right, emo + If Twolk on the | (negative) graph From et to | eg. y= - x4! right, I wolk downhill |” « Graph is descending If x increases, | y decreases. (decreasing). “ m=0 +—+— + Line runs horizontally, / mis | | a 24 Powered by CamScanner dycintercept _ To find the x-intercept: > let y=0 and find x | To find the y- intercept: > let x=0 and find y Horizontal lines Equation: eg. oie -3 « Cuts y-axis + Parallel to x - axis + Gradient = 0 Tip: Lf a line intersects (cuts) the y-axis only > then the equation contains a y only. 203 Powered by CamScanner Equation: og be? + Parallel to y-axis ; . Gradient is undefined Tip: If a line intersects (cuts) the x - axis op| = then the equation contains an x only Parallel (| Fis parallel to g: . » £4 “Fil ke i ° m, =m, (=2) 204 Powered by [@ CamScanner , pendicular (1) lines y cis perpendicular to h: tah m, X m,= -I | | a2x-9 £ . gradient, of F x gradient of h = -1 Collinear points . A,B and C are collinear, + This means you can draw a straight line through all 3 points. A * Mag = Mac = Mac + The gradients of AB, BC and AC are all the same, A, Band C all lie on the same straight line. (‘cot = together; "linear" = on a line) Powered by CamScanner geomet oO gles and lines f straight lines | Tria co Statement Redan A=B=C=6o" | (AARC is equilateral) Cc B an A B=C (Zs Opposite equal sides) OR: - (equal sides; equal zs) 8 A AB=AC {sides opposite equal zs OR: , c (equal 2s, equal sides) J~\ A+B+C=1g0° | (interior Zs of A) 8 c A C,=A+B (exterior £ of A)

you also have +0 say which lines are |I, + Alt. Zs and corresp. 2s are only = when the lines are |I. + Co-int. Zs are only supplementary (= 180°) when the lines are ||. IMPORTANT: |. First state what = what, Write down an equation. 2. Then write down your reason, How do you know these are =? = There is often more than | method, Your reason just needs to match nag Whatever you are stating, Powered by CamScanner f 2D objects Gomer) ol spties oF quadrilaterals | gE re slog” - « both pairs oF opp, sides = | — © both pairs of Opp. sides || ¢ both pairs of Opp. Ls = ° diagonals bisect each other both pairs of Opp. sides 2 « both pairs of opp. sides || + both pairs of Opp. Zs = ° diagonals bisect each other “AND: \s diagonals = |e each interior 2 = 90° Rhombus e both pairs of opp. sides = e both pairs of opp. sides ll ¢ both pairs of opp. 2s = ° diagonals bisect each other AND: | e all 4 sides = . diagonals intersect L | . diagonals bisect ds | Powered by (9 CamScanner ! | Oquare Trapezium + both pairs of “OPP. sid | « both pairs of opp + both pairs of opp. 1, . diagonals bisect each AND: . diagonals = + each interior £ = oe AND: e all 4 sides = . diagonals intersect, | diagonals bisec bisect zs si te, ; | pair of opp. sides les || . diagonals intersect L * both pairs of adjacent sides = * | pair of opp. ds = | + longer diagonal bisects | shorter diag onal + longer dogo bisects 48 Powered by CamScanner em OT ye 4cm % is the hypotenuse: A Re Vy y? (Pyth) is0m x is not the hypobenuse 17? = x? 415? (Pyth) 47cm x? =IF°-15? (Pyth) Ina right - angled A: (gest side)? = (short side)? + (other short side)! In an obtuse - angled A: longest side)? > (short side)? + (other short side)? | In an acute - angled A: Inst ide)? < (short side)? + (other short, side) Remember: — of ten more than | me netho J. Your reasons just need +o match your s statements _—_—— Powered by CamScanner Congruence and similarity « side, side, side (SSS) side, angle, side (SAS or SZS) + angle, angle, side (AAS or ZZS) « 90°, hypotenuse, side (ao"HS or RHS) « angle, angle, angle (AAA or zzz) e sides in proportion ce Powered by Conon E (g55)— «iB c | D el The order of the letters is important. A and F both lie opposite the iside with jhash mark (BC and DE, which are equal). |, . Aand F are corresponding Ls ("buddies") as they lie opposite corresponding sides. » Therefore you write A and F in the same position in AABC= AFDE. In the same way: | 8 and B both lie opp. side with 2 hash marks. (ond E both lie opp. side with 3 hash marks, You could also write: ABAC=ADFE, for example. Order of + A's letters doesn't matter, as long as Corresponding letters are in corresponding positions Powered by CamScanner ene” 4 x side a es we (= side x side) E- Area = 5 x x diagonal x diagonal 2 Rage “perimeter = 2 + 2b =2(£+b) Ld Areas & x b Perimeter = side + side + side Area = sbase x Lh — 7S Powered by (3 CamScanner Circumference = 27 Area = tr? Tip: Both formulae have a 2 somewhere, Deena eee Circumference: 211r Area: tr? SU EUUDGET AEDST UST SEPSUNE IV, SSS Ipemree ee Measure perimeter in cm, Measure area in cm? j m, etc. (not squared) m?, ete. Just rin formula (not |r? in Formula squared) © Pavallelogram Perimeter = 24 + 2b Area=base x Lh Perimeter =all the sides Area = tb) x ‘Lh 296 Powered by 9 CamScanner perimeter =4 x side A / —h jyea= BASE X ih _#——. | fs yy Area = 5 x diagonal x diagonal 2 Perimeter = (2 x short side) + (2 x long side) fre = , x diagonal x diagonal 2 Kite with 4 equal sides . rhombus Square, rhombus and kite: Area = 5 x diagonal | x diagonal 2 297 Powered by 9 CamScanner ace area and volume su Rectangular prism Surface areq Surface area =2 rectangles + 2 rectongles + 2 rectangles = 2(€ x h) + alb x h) + (£ xb) = 2(th) + albh) + 2(£b) Volume | Volume = area of base x h =t{xbxh = tbh 321 Powered by CamScanner Cube (a special rectangular prism) Surface area =6 squares 2 =6 x side side Volume =area of base x h 4) = side x side x side = side" side 322 4 i , — Powered by 9 CamScanner Triangular prism pds + rectangle + rectangle + rec tangle aeave A;bxh) + + (€xb) + (xb) + (£xb) 'ealsbh) - th + th +. b Volume = area of base x H =area A xH H = tbxhxH (hed height of A; H = height of prism) 323 Powered by 9 CamScanner Cylinder Surface area Think of the label around a tin of sweetcorn (tin = cylinder). If you remove the label and lay it down flat, it looks like this: Label is a rectangle when you remove it, - TSA = circle on top + circle below + rectangle (total surface area) Area of rectangle = length x breadth + Length of rectangle = circumf, (2mn) of circle (as the label Folds around the tin) « Breadth of rectangle = height (h) of tin a8 (cylinder) — Powered by CamScanner r tA-O+O+[ ] eur’ + tr? + “xb! eur? + Tr? + 2tpxh | = 2? +2Trh Volume Jolume = area of base x h =r xh h =arh NB! When you calculate volume: . Triangular prism > base is always a A * Cylinder = base is always circle Note: TSA = total surface area os Powered by CamScanner « Shift up or down > y + Or - eg, (2, - 3) shifts 2 up 2 y- coordinate + 2 = (2, -3+2) = (2-0) Rule: (x; y) > (x; y+2) Tf a point shifts 2 units down = Rule: x. y)> © ShiFt right or left > x: + on - eg. (2; -3) shifts 2 leFt = x-coordinate - 2 > (2-2, -3) = (0; -3) | Rule: (x; y) + (2-2, y) | TF a point Shifts 2 units £0 the night | = Rule: (x, y)>(ee2, y) | Powered by (3 CamScanner Probability Definitions: PIA) probability / = the chance that A will happen => P(A)= a | |= 0«< PIA) < nA) n(S) Outcome “something newer happen ‘the mie of times something \(event A) can happen (the paper of outcomes) sample space > all possible outcomes (everything that could possibly _| happen) the total umber ee ee in the sample space | Randomly bina (without | looking) Powered by CamScanner

You might also like