Question

y=x²-5x+4

y=-x²+4x-4

y=x²-1

y=x²-3x

Answer 1

y = x² - 5x + 4

Δ  = b² - 4ac
Δ = (-5)² - 4 . 1 . 4
Δ = 25 - 16
Δ = 9

x' = -b + $\sqrt {\Δ}$ / 2a
x' = -(-5) + $\sqrt {\9}$ / 2.1
x' = 5 + 3 / 2
x' = 8 / 2 = 4


x'' = -b - $\sqrt {\Δ}$ /2a
x'' = -(-5) - $\sqrt {\9}$ /2.1
x'' = 5 - 3 / 2
x'' = 2/2 = 1