Tentukan nilai dan titik stasioner fungsi f (x)=x³-6x²+9x+1
Jawab:
turunan
titik stationer, jika f'(x) = 0
f(x) =x³-6x²+9x+1
f'(x)= 0
3x² -12x + 9= 0
3(x² – 4x + 3) =0
3(x – 1)(x – 3) =0
x= 1 atau x = 3
nilai statiober
f(x) =x³-6x²+9x+1
f(1) = (1)³- 6 (1)²+ 9(1) + 1
f(1) = 1 – 6 + 9 +1
f(1) = 5
f(3) = (3)³ – 6 (3)²+ 9(3) + 1
f(3) = 27- 54 + 27 + 1
f(3) = 1
nilai stationer f(x)= 1 dan 5
titik stationer (x, f(x)} = (1, 5) dan (3, 1)