Week 6——Developing and Applying the Quadratic Formula

use the way that we learned to make ax²+bx+c=0 change to

$\frac{-b+-\sqrt{b^2-4ac}}{2a}$

Ex:

x^2+9x -2=0

use the formula that we just make

a=1，b=9，c=-2

$\frac{-9+-\sqrt{9^2-4\cdot1\cdot-2}}{2\cdot1}$ $\frac{-9+-\sqrt{81+8}}{2}$ $\frac{-9+-\sqrt{89}}{2}$

finished

so we can use this formula to solve the question easily and correctly

Recent Posts