2017 ONE(b)

Achievement
Question
Find the gradient of the tangent to the curve y=e2xx+2y = \dfrac{e^{2x}}{x + 2} at the point where x=0x = 0.

*You must use calculus and show any derivatives that you need to find when solving this problem.*
Official Answer
dydx=(x+2)2e2xe2x(x+2)2\dfrac{dy}{dx}=\dfrac{(x+2)\cdot 2e^{2x}-e^{2x}}{(x+2)^2}

At x=0x=0 dydx=2×214=34\dfrac{dy}{dx}=\dfrac{2\times 2-1}{4}=\dfrac{3}{4}
Grading Criteria

Achievement (u)

  • Correct solution with correct derivative.

Merit (r)

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Excellence T1

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Excellence T2

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Video Explanation
NCEA Level 3 Calculus Differentiation 2017 NZQA Exam - Worked Answers by infinityplusone(starts at 1:42)
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