jika f (x)=2x (pangkat 2) + 3x -5 dan g (x) = 3x-2 agar (g○f)(a)= -11,maka nilai a yang positif adala?

(gof)(a) = 3(2a²+3a-5)-2 = -11
= 6a²+9a-15-2+11 = 0
= 6a²+9a-6 = 0
= (6a-3 )(a+2)
a = 3/6 = 1/2 atau a = -2
jadi a yang bernilai positif a = 1/2