5 marksVectors
CAPE Pure Mathematics Unit 1 · May/June 2005 · Paper 2 · Question 4(b)(ii)
The position vectors of two points A and B relative to the origin O are a = 4cos²θi + (6cosθ-1)j and b = 2cosθi - j.
By using the identity in (b)(i) above, find the value of θ, 0 ≤ θ ≤ π/2, such that a and b are perpendicular.
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