Exercise algebra.equations.quadratic.no-abc
Description
solve a quadratic equation without abc-formula
Derivation
![](http://ideas.cs.uu.nl/images/external.png)
0 == -3*x+6+x^2-3*x
⇒ algebra.equations.linear.flip-3*x+6+x^2-3*x == 0
⇒ algebra.equations.linear.merge-6*x+6+x^2 == 0
⇒ algebra.equations.quadratic.prepare-splitx^2-6*x+9 == 3
⇒ algebra.equations.quadratic.left-square(x-3)^2 == 3
⇒ algebra.equations.coverup.powerx-3 == sqrt 3 or x-3 == -sqrt 3
⇒ algebra.equations.coverup.onevar.minus-leftx == 3+sqrt 3 or x-3 == -sqrt 3
⇒ algebra.equations.coverup.onevar.minus-leftx == 3+sqrt 3 or x == 3-sqrt 3