How can you solve something like $-x^2 + 7x - 15$??
Take out $-1$ as a factor.
What is the result of taking out $-1$ from $15 + 13x - 4x^2$??
$$ -(4x^2 - 13x - 15) $$
How can you solve something like $x^4 + 5x^2 - 36 = 0$??
Substitute $a = x^2$.
Substitute $a = x^2$ into $x^4 + 5x^2 - 36 = 0$??
$$ a^2 + 5a - 35 = 0 $$
How could you solve something like $x - 9\sqrt{x} + 24 = 0$??
Substitute $a = x^{\frac{1}{2}}$.
Substitute $a = x^{\frac{1}{2}} into $x - 9\sqrt{x} + 24 = 0$??
$$ a^2 - 9a + 24 $$
What is the name for a quadratic in disguise??
A sneaky quad.
What are the two criteria for an equation being a sneaky quad??
- Only two $x^n$ terms
- One power of $x$ is double the other.
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date: 2020-10-03 12:25
tags:
- '@?maths'
- '@?public'
title: Maths - Quadratics Tips and Tricks