Analyzing Coordinate Geometry with Collinearity and Trigonometric Calculations
Explore points and lines through coordinates, collinearity assessment, differentiation, integration, logarithm simplifications, and trigonometric expressions in mathematics practice exam.
Analyzing Coordinate Geometry with Collinearity and Trigonometric Calculations
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Presentation Transcript
Outcome 1 1. (a) A, B and C have coordinates (1, 2, 3), (4, –4, 12) and (5, –6, 15). (i) Write down the components of AC (ii) Hence show that the points A, B and C are collinear. i) AC = c – a ii) BC = c – b ( ) ( ) ( ) ( ) 5 -6 15 4 -4 12 5 -6 15 1 2 3 – – ( ) ( ) = 1 -2 3 = 4 -8 12 Thus AC = 4BC with common point C, therefore collinear (could also have used AB)
KL = 2LM l – k = 2(m – l) l – k = 2m – 2l 3l = 2m + k ( ) ( ) -1 0 3 5 -3 6 + = 2 ( ) 9 -6 15 3l = coordinates L (3,-2,5) ( ) 3 -2 5 l =
a) 2(3) + -1(0) + 2(4) = 14 b) cosϴ = PQ . PR PQ = √22 + (-1)2 + 22 PQ PR = √9 = 3 cosϴ = 14 PQ = √32 + 02 + 42 3(5) = √25 = 5 ϴ = cos-1(14/15) ϴ = 21.00 Threshold 9 out of 12
Outcome 2 3. (a) Differentiate –3sin x with respect to x. → -3cosx dy/dx =-½sinx (b) Given y = ½cosx, find dy/dx
4. Find f/(x) when, f(x) = (x + 3)-5 let y = U-5 where U = x + 3 dy/dU = -5U-6dU/dx = 1 dy/dx = -5U-6.1 = -5(x + 3)-6
5) a) Find ∫4cosx dx → 4sinx + c b) Integrate –¾sinx with respect to x → ¾cosx + c
3 ∫ c) Evaluate (x – 1)4 dx 2 [ ] 3 = (x – 1)5 1(5) 2 – (2 – 1)5 = (3 – 1)5 5 5 = 31/5 units2 Threshold 8 out of 11
Outcome 3 6. (a) Simplify loga12 + loga2. loga24 (b) Simplify 5 log82 – log8 4. = log825 – log84 = log832 – log84 = log88 = 1
loge4 7) a) If x = loge7 find an approximation for x x = 1.40 (using calculator) (b) Given that log10y = 3.4, write down an expression for the exact value of y. y = 103.4 (c) If y = 102.9, find an approximation for y. 794.3 (using calculator) Threshold 5 out of 8
Outcome 4 8) Express 2cosx + 3sinx in the form kcos(x-α) where k>0 and 0≤α<3600 2cosx + 3sinx kcos(x – α) = kcosxcosα + ksinx sinα equating coefficients kcosα = 2, ksinα= 3 k = √(22 + 32) tanα = 3/2 tan-1(3/2) = 56.30 Quad i → α = 56.30 →√13cos(x – 56.30) = √13 Threshold 3 out of 5