No 26 sama 28 gimana caranya kak?

Mapel : Matematika
Kelas : X SMA
Bab : Fungsi Komposisi dan Fungsi Invers

Pembahasan :
26||

f(x) = 2 Sin (1/2 x)

Note 1/3 pi = 1/3 . 180 = 60°
f(60°) = 2Sin (1/2 . 60)°
f(60°) = 2Sin 30°
f(60°) = 2(1/2)
f(60°) = 1

28||

f(x) = 6Sin (2x + 10)°
f(70°) = 6Sin (2.70+ 10)°
f(70°) = 6Sin 150°
f(70°) = 6(1/2)
f(70°) = 3