Question

Which of the following trigonometric function derivatives is correct?

(a) \(\frac{d(sinx)}{dx}=-cosx\)

(b) \(\frac{d(secx)}{dx}=tanx\)

(c) \(\frac{d(tanx)}{dx}=sec^2 x\)

(d) \(\frac{d(cosx)}{dx}=sinx\)

The question was posed to me in quiz.

I want to ask this question from Total Derivative topic in division Partial Differentiation of Engineering Mathematics

Answer 1

Right answer is (c) \(\frac{d(tanx)}{dx}=sec^2 x\)

To explain: Correct forms of Trigonometric Derivative Functions

 \(\frac{d(sinx)}{dx}=cosx\)

 \(\frac{d(cosx)}{dx}=-sinx\)

 \(\frac{d(secx)}{dx}=secxtanx\)

 \(\frac{d(tanx)}{dx}=sec^2 x\)