Find the coefficient of x minus pi over 4 in the Taylor series for f(x) = tan(x), centered at pi over 4

Question

Find the coefficient of  in the Taylor series for f(x) = tan(x), centered at  

A	2
B
C
D

Answer 1

The Taylor Series is f(π/4) + f'(π/4)(x - π/4) + (f"(π/4) / 2!)(x - π/4)² + (f'''(π/4) / 3!)(x - π/4)³ + ...

So, the desired coefficient is f'(π/4) = sec²(π/4) = 2