Question: how to solve quadratic equation shortcut?
Answer: When the roots of the quadratic equation ax2+bx = c are negative reciprocals of each other, then c = -a . If they have both the roots common, then a/a1 + b/b1 + c/c1. The square root of any negative number will be an imaginary number like √-25 = √(-1)× 25 = √-1×√ 25 = 5i.