Untuk F(x)=x^3+3x ,carilah nilai F(1+h)-F(1)

F(x) = x³+3x
Dit : f(1+h) – F(1)

Pertama cari f(1+h)
F(x) dan f(1+h)
Maka semua x diganti dengan 1+h
(1+h)³ + 3(1+h)
(1+h)²(1+h)+3(1+h)
(h²+2h+1)(1+h)+3(1+h)
h²+h³+2h+2h²+1+h+3+3h
h³+3h²+6h+4

Cari f(1)
1+3 = 4

Maka
F(1+h)-f(1)
= h³+3h²+6h+4-4
= h³+3h²+6h

*cmiiw*

F(x) = x (x^2 + 3)

F(1+h) = (1+h).[(1+h)^2 + 3]
F(1+h) = (1+h).(h^2 + 2h + 4)
F(1+h) = h^3 + 3h^2 + 6h + 4

F(1) = 1.(1 + 3) = 4

F(1+h) – F(1) = h^3 + 3h^2 + 6h + 4 – 4
= h^3 + 3h^2 + 6h