What are the roots if the equation 4(x^2-1)= -3x?

1 Answer
Mar 31, 2017

x= ( -3 +- sqrt73) / 8

Explanation:

4 * ( x^2 - 1) = - 3x
4x^2 - 4 = -3x
4x^2 + 3x - 4 = 0
Which follows the form of: ax^2 + bx + c =0

So you solve it using the discriminant

Δ= b^2 - 4 * a * c
Δ = 9 + 64 = 73
Δ > 0 so it has two different solutions

x1= ( -b + sqrtΔ ) / (2 * a)
x1= ( -3 + sqrt73) / 8

x2= ( -b - sqrtΔ ) / (2 * a)
x2= ( -3 - sqrt73) / 8