Question

Solve the following quadratic equation using formula method only 

x² - 6x + 4 = 0

Answer 1

x² - 6x + 4 = 0

a = 1 ; b = - 6 ; c = 4

D = b² - 4ac 

= (-6)² - 4(1)(4)

= 36 - 16

= 20

x = `(- "b" ± sqrt ("b"^2 - 4 "ac"))/(2a)`

x = `(6 +- sqrt 20)/2`

x = `(6 +2 sqrt 5)/2` , x = `(6 - 2 sqrt 5)/2`

x = `3 + sqrt 5`  ,   x = `3 - sqrt 5`