Question

What is the derivative of the function f(x) = e^tanx + ln(secx) - e^lnx at x = π/4?

a. e/2 

b. e 

c. 2e 

d. 4e

Answer 1

Correct option c. 2e  

Explanation:

f(x) = e^tanx + ln(secx) - x

f'(x) = e^tanx. sec²x + (secxtanx)/secx - 1

f'(π/4) = 2e + 1 - 1 = 2e