diketahui g(x )=x^2+2x-3, (g o f)(x) = x^2-10x+21dan f(1)=3 tentukan fungsi f(x) yang memenuhi

(g○f)(x)=g(f(x))=[f(x)]²+2f(x)-3
x²-10x+21=[f(x)]²+2f(x)-3
x²-10x+24=[f(x)]²+2f(x)
x²-10x+24={f(x)+1}²-1
x²-10x+25={f(x)+1}²
(x-5)²={f(x)+1}²
±(x-5)=f(x)+1

f(x)=x-5-1=x-6
f(x)=-x+5-1=4-x