Question

If f(x) = cosec x + cot x, find $\rm f'\big(\frac{\pi}{4}\big)$.

Answer 1

Answer:

-2 - √2

Step-by-step explanation:

Hi,

Given that f(x) = cosec x + cot x

We know that d/dx(cot x) = - cosec² x

and d/dx ( cot x) = -cosec x cot x

f(x) = cosec x + cot x

f'(x) = -cosec²x - cosec x.cot x

f'(π/4) = - cosec²(π/4) - cosec(π/4)cot(π/4)

= -2 - √2.

Hence, the value of f'(π/4) is -2 - √2.

Hope, it helps !