Question

помогите! Прошу!!! Очень надо)

Answer 1

f(x) = tg²x - 3
f'(x) = 2 tgx * 1/ Cos²x = 2Sinx/Cos³x
f'(П/4) = 2SinП/4 / Cos³П/4 = (2 * 1/√2) / (1/√2)³ = √2 / (1/2√2) = 1/2