1) so that students can observe the derivation of the quadratic formula, and have an idea of what is going on; and

2) for manipulating equations and expressions at an algebra II or precalc level (ex to find center and radius for x^2 + 6x + y^2 – 10x = 1 or to factor x^4 + 4 )

At the Algebra I level, the first reason makes sense – I wouldn’t want a kid to take a formula on faith – but not for graphing, when there are perfectly powerful tools available that are far less complex.

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