Exercise algebra.equations.quadratic.no-abc
Description
solve a quadratic equation without abc-formula
Derivation
![](http://ideas.cs.uu.nl/images/external.png)
x^2-x+1/4 == 121/4
⇒ algebra.equations.quadratic.left-square(x-1/2)^2 == 121/4
⇒ algebra.equations.coverup.powerx-1/2 == 11/2 or x-1/2 == -11/2
⇒ algebra.equations.coverup.onevar.minus-leftx == 6 or x-1/2 == -11/2
⇒ algebra.equations.coverup.onevar.minus-leftx == 6 or x == -5