Limits, Continuity & Differentiability
General
Grade None
Question:
<p>Let a > 0 be a root of 2x2 + x −2 = 0.
If
lim
x→1/a
16
1 −cos(2 + x −2x2)
1 −ax2
= α + β
√
17,
where α, β ∈Z, then α + β is equal to</p>
Step-by-Step Solution
Key Concept: General
<p>The official module answer key gives the value 170.</p> Shortcut / Fast View This question is built around using the positive root of 2a2 + a -2 = 0 inside a trigonometric small-angle limit.
Correct Answer: (170)