Question

Fungsi f dinyatakan dalam bentuk f(x) ax+b.jika diketahui f(2) =11 dan f(3)=15,maka tentukan:1.nilai a dan b. 2.fungsi f. nilai f(5)

Answer 1

•f(x)=ax+b
•f(2)= 11
2a+b=11
•f(3)=15
3a+b=15

3a+b=15
2a+b=11
_________ - (dieliminasi)
a = 4
• 2a+b=11
2x4 + b = 11
8 + b = 11
b=11-8= 3
f(x)= 4x+3
•f(5) = 4x5 + 3 = 23

Answer 2

1.
f(x) = ax+b
11 = 2a+b
15 = 3a+b
—————— -
-4 = -a
a = 4
substitusi a ke 4
11 = 2.4 + b
11 - 8 = b
3 = b

a = 4
b = 3

2. f(x) = 4x + 3

f(5) = 4.5 + 3
f(5) = 23