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Before the midterm

Applying the power rule to an exponential

The habit: xn brings the n down, but ax has the variable upstairs and differentiates to ax log a.

8 practice questions are built to catch it, in 3 topics.

See it fail in a figure: Not the power rule, in the exponential and trigonometric functions lesson

Practise against it: 6 questions

What it looks like

A question from exponential and trigonometric functions, with the answer this slip gives beside the right one.

Introductory1 mark · 2 min

Which of the following is the derivative of g(x)=3xg(x) = 3^{x}?

With the slip
x⋅3x−1\displaystyle x\cdot 3^{x - 1}
Worked through
3xlog⁡3\displaystyle 3^{x}\log 3

x · 3x−1 treats the x in 3x as a fixed exponent. Here the base 3 is fixed and x varies: write 3x = ex log 3 and use the chain rule.

See the worked solution

Where it comes up

Practise against it

Each of these has an answer this slip gives. Work them on paper: if you fall into it, the verdict names it and the question comes back in review.

  1. 01
    Which of the following is the derivative of h(x)=x2exh(x) = x^{2}e^{x}?

    Exponential and trigonometric functionsIntroductory

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