Question

Di ketahui rumus fungsi f(x) = ax+b . Jika nilai f(1)= 7 dan f(3) = 11 tentukan : a. Nilai a dan b
B. Bentuk fungsinya
C. Nilai f(-1)

Answer 1

F(x) = ax + b
f(1) = 7 --> a+b = 7
f(3) = 11--> 3a + b = 11
kurangkan -2a = -4
a = 2
a + b = 7 --> b = 7-2
b = 5

b). f(x) = ax+ b --> f(x) = 2x + 5
c) f(-1) = 2(-1)+ 5 = 3