jika f(x)=x²+1 dan (gof) (x) =4x-3 maka g(x) ?

let f(x) = u
u = x^2 + 1
x = √(u-1)

jadi 
gof (x) = 4x - 3

subtitute: x ke gof(x)

= 4(√(u-1))-3

ganti u ke x
f(x) = 4√(x-1) - 3