Question

Diketahui f(x)=ax+b tentukan fungsi f(1)=3 dan f2=5

Answer 1

Subs 1 > x maka, 1 = a+b (pers. 1)
subs 2 > x maka, 5 = 2a+b(pers. 2)

pers 2 - pers 1
-4 = -1x
x = 4 (pers 3)

subs pers 3 ke pers 1
1 = 4 + b
b = -3

jadi, f(x) = 4x - 3

Answer 2

F(1)=3
f(2)=5

a=(5-3) / (2 -1)
a= 2 / 1
a= 2

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

maka rumus fungsinya
a=2
b=1
f(x)=ax+b
f(x)=2x+1