1.Dik=g(x)=9-3x^2 ,jika g(f(x)) = -3x^3+6x^2+24x-15 . tentukan f(x) dan f(-3) 2.g(x)=x^2-1 dan f(g(x))=x^4 , tentukan f(4) 3.f(x)=x-1/x+1 , g(x)=3x . tentukan n

1.Dik=g(x)=9-3x^2 ,jika g(f(x)) = -3x^3+6x^2+24x-15 . tentukan f(x) dan f(-3)
g(f(x))=-3x^3+6x^2+24x-15
9-3(f(x)²=-3x^3+6x^2+24x-15
-3f(x)² = -3x^3+6x^2+24x-15-9
f(x)²=-3x^3+6x^2+24x-15 / -3
f(x) ²= x³-2x²-8x+5
f(x) = √(x³-2x²-8x+5)
f(-3)=√((-3)³-2(-3)²-8(-3)+5)
=√(27-18+24+5)
=√38


2.g(x)=x^2-1 dan f(g(x))=x^4 , tentukan f(4)
f(x²-1)=x⁴
misal
t=x²-1
x²=t+1
x= √(t+1)
f(x) = [√(x+1)]⁴
f(4)=[√(4+1)]⁴
=(√5)⁴
=25