jika f(x) = x cos 2x, maka f^1 (- 1/4 phi) =
Matematika
yulisrimulyani2
Pertanyaan
jika f(x) = x cos 2x, maka f^1 (- 1/4 phi) =
1 Jawaban
-
1. Jawaban rayyadinne
f(x) = x.cos2x
f'(x) = 1.cos2x + x.(-2sin2x)
= cos2x - 2xsin2x
f'(-pi/4) = cos(-pi/2) -2(-pi/4)sin(-pi/2)
= 0 + pi/2.(-1)
= -pi/2