1.fungsi x dinyatakan rumus f(x)=ax+b jika f(3)=-4 dan f(4)=-7 tentukan:
a.rumus fungsi
b.f(-1)
Soal
Jawaban:
f(x)=ax+b
f(3)=3a+b=-4
f(4)=4a+b=-7-
-a=3
a=-3
3a+b=-4
b=-4-3a=-4-3(-3)=-4+9=5
f(x)=-3x+5
f(-1)=-3(-1)+5=3+5=8
f (x) = ax + b
f (3) = 3a + b = -4
f (4) = 4a + b = -7
——————— –
-a = 3
a = -3
3a + b = -4
3(-3) + b = -4
-9 + b = -4
b = -4 – (-9)
b = -4 + 9
b = 5
a) Rumus fungsi
f (x) = ax + b
f (x) = –3x + 5
b) f (x) = –3x + 5
f (–1) = –3(–1) + 5
f (–1) = 3 + 5
f (–1) = 8
semoga membantu