If it takes less than a minute to check if an expression is factorable, why not? Before running the tedious formula.

Special cases? I have none. One method for all, allows to check if an expression is factorable before doing the work.

Try this: Teaching Factoring – Should we? and I’d be happy to point you towards a discussion of trinomial factoring by breaking the middle.

]]>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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