The quadratic equation 2x^2 + bx + 82 has a double root. Find all possible values of b.
In my answer, I will assume the discriminant in the quadratic formula is 0.
The way to solve is:
b^2-4ac=0
b^2=4ac
b^2=4*2*82
b=+- sqrt(656)
b=+- 4sqrt(41)
+189 
