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1 lesson for “The quadratic formula”

The quadratic formula · Further topics

Not every quadratic factors over the integers. The quadratic formula works for all of them, and it only asks you for three careful numbers.

Solving quadratics by factoring · Further topics

x^2 - 5x + 6 = 0 has two solutions, not one. Once the quadratic is factored, a product equal to zero tells you exactly where they hide.

Distance and midpoint · Further topics

Two points give you a right triangle in disguise. The legs are the changes in x and y; the distance is the hypotenuse.

The discriminant · Further topics

Before solving a quadratic, the discriminant can tell you how many real answers it will have. One number, three cases.

Completing the square · Further topics

A perfect square like (x + 3)^2 is easy to solve. Completing the square builds one on purpose, right in the middle of an equation.

Acceleration · Foundations

You said a car cruising at 55 mph has lots of acceleration because it is fast. Constant speed on a straight road is zero acceleration.

Percent yield · Further topics

If 60 g was expected and 45 g appeared, is that 75% or 133%? The order of the fraction is the whole lesson.

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