f(x) = x2 - 4x + 7, maka tentukan:
a. f(2)
b. f(2x - 3)
Jawab:
f(x) = x2 – 4x + 7
a. f(2) = 22 – 4 . 2 + 7
= 4 – 8 + 7
f(2) = 3
b. f(2x – 3) = (2x – 3)2 – 4(2x – 3) + 7
= 4x2 – 12x + 9 – 8x + 12 + 7
f(2x – 3) = 4x2 – 20x + 28