Are you sure? Here in Germany the basic fact that the two solutions of a quadratic equation must multiply / sum to the two coefficients is taught in high school, but I mean this is only useful for small numbers that are easily factorized.
But the more useful and well-known quadratic formula is always derived with “completing the square”, not the method described in the article (which I think is quite neat). Especially since I would suspect many students never really grasp “completing the square” and just skip to memorizing the quadratic formula.
Comments
Are you sure? Here in Germany the basic fact that the two solutions of a quadratic equation must multiply / sum to the two coefficients is taught in high school, but I mean this is only useful for small numbers that are easily factorized.
But the more useful and well-known quadratic formula is always derived with “completing the square”, not the method described in the article (which I think is quite neat). Especially since I would suspect many students never really grasp “completing the square” and just skip to memorizing the quadratic formula.