How do you show some quadratic polynomials are always greater than 0?

Usually, there are two ways to solve this kind of problems. You could re-arrange the polynomial, make it become a square plus a constant, then the polynomial is greater or equal to the constant since a square of anything is greater or equal to 0.The second way is to use the formula. I would also encourage students to derive the formula themselves.

LW
Answered by Luke W. Maths tutor

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