f(x)=x2-6x+5 nilai minimumnya berapa?

x^2 - 6x + 5 = ( x-1)(x-5) x=1 => 0 × (-4) = 0 x=2 => 1 × (-3) = (-3) x=3 => 2 × (-2) = (-4) x=4 => 3 × (-1) = (-3) jika x > 5 hasilnya akan positif.. maka nilai minimumnya = (-4)