Nilai minimum fungsi y=x^2 – (m-3)x + (m+3) adalah 6.tentukan f(2)
Cari dulu nilai m nya :
Berarti :
x = -b/2a = (m-3)/2
F(x) = y = 6
x^2- (m-3)x + (m+3) = 6
((m-3)/2)^2 – (m-3).((m-3)/2 + m+3 = 6
((m^2-6m+9)/4) – ((m^2-6m+9)/2 + m + 3 = 6
((m^2- 6m + 9) – (2m^2- 12m + 18) + (4m+12)/4)) = 6
-m^2+ 10m + 3 = 24
-m^2+ 10m = 21
m^2- 10m + 21 = 0
(m-3) (m-7) = 0
m = 3 atau m = 7
Yg memenuhi m = 7
Jadi.F(x) = y = x^2 – 4x + 10
F(2) = 2^2 – 4(2) +10 = 6