F'(x) = 1 - 6x dan f(0) = 8

F'(x) = 1 - 6x
Cari f(x) pake integral
Jadi,
F(x) = x - 3x^2 + C

Jika
F(0) = 8

Maka,
F(0) = x - 3x^2 + C
8 = 0 - 3(0) + C
8 = C

Jadi,
F(x) = x - 3x^2 + 8

Nb : C = konstanta