Diketahui fungsi f(x)=2x+5,g(x) =2x ²+3x-5, h(x) =x-4.tentukan A. (fogoh) (x) B. (fogoh) (-1)

Jawab:
A.
(fogoh)(x)
/pertama cari dahulu f{g(x)}/
f(x) = 2x-5
f{g(x)} = 2(2x^2+3x-5)+5
f{g(x)} = 4x^2+6x-10+5
f{g(x)} = 4x^2+6x-5
/misalkan f{g(x)}=i(x)/
i(x) = 4x^2+6x-5

/lalu cari i{h(x)}/
i(x) = 4x^2+6x-5
i{h(x)} = 4(x-4)^2+6(x-4)-5
i{h(x)} = 4(x^2-8x+16)+6(x-4)-5
i{h(x)} = 4x^2-32x+64+6x-24-5
i{h(x)} = 4x^2-26x+35

Jadi, (fogoh)(x) = 4x^2-26x+35

B.
(fogoh)(x) = 4x^2-26x+35
(fogoh)(-1) = 4(-1)^2-26(-1)+35
(fogoh)(-1) = 4+26+35
(fogoh)(-1) = 65

Semoga bermanfaat.... :)