How do you solve 3x^2-12x+11=0 using the quadratic function?

2 Answers
Jun 27, 2018

x=(6+-sqrt3)/3

Explanation:

The quadratic equation is

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

for a quadratic taking the form

ax^2+bx+c=0

So for this equation it is

x=(-(-12)+-sqrt((-12)^2-4*3*11))/(2*3)

x=(12+-sqrt(144-132))/(6)

x=(12+-sqrt(4*3))/6

x=(6+-sqrt3)/3

Jul 12, 2018

color(blue)(x = 2 + 1/sqrt3, 2 - 1/sqrt3= 2.5774, 1.4226

Explanation:

Quadratic formula to find the roots x = (-b +- sqrt D) / (2a) where D is the discrimination to decide whether the roots are real or imaginary.

D = b^2 - 4 a c

Given equation is 3x^2 -12x + 11 = 0

a = 3, b = -12, c = 11, D = -12^2 - (4 * 3 * 11) = 12

x = (12 +- sqrt 12) / 6

x = 2 +- (1/sqrt3)

color(blue)(x = 2 + 1/sqrt3, 2 - 1/sqrt3= 2.5774, 1.4226