Question

Diketauhi fungsi f(x+1)=x^2-1 g(x)=2x. maka rumus (gof)(x) adalah

Answer 1

ubah dulu f(x+1)=x^2-1, jadi f(x):
f(x+1) = x² - 1
misal:
x+1 = y
x = y - 1

f(y) = (y - 1)² - 1
f(y) = y² - 2y + 1 - 1
f(y) = y² - 2y
f(x) = x² - 2x

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rumus (gof)(x)
= g(f(x))
= g(x² - 2x)
= 2(x² - 2x)
= 2x² - 4x

Kalo Gasalah sih -_-