Daily Archives: April 30, 2007

`x^2` Solving the quadratic equation. Suppose `ax^2+bx+c=0` and `a!=0`. We first divide by `a` to get `x^2+b/ax+c/a=0`. Then we complete the square and obtain `x^2+b/ax+(b/(2a))^2-(b/(2a))^2+c/a=0`. The first three terms factor to give `(x+b/(2a))^2=(b^2)/(4a^2)-c/a`. Now we take square roots on both … Continue reading →