MATHEMATICS

QUADRATIC FUNCTIONS: Completing the Square, pt. 2

All you have to do now is compare the new equation to a^2 + 2ab, the same way we did in the previous method. But here, we exclude A and look only at what's inside the brackets. 

To find a, we can use a shortcut. Since we'll always remove the coefficient of x^2 to reduce it to x^2, a is always going to equal x. So we can skip that step, and move straight to finding b.

Now, we just follow the same method: b is found through dividing 2ab by 2a.

We condense the equation back into (x + 1)^2, subtract b^2 from the whole equation, and then add c to find C (note: I forgot to add an " = 0 " at the end of this expression. You'll want to write it for every step just to be sure.) 

Which gives us our completed equation!

Trying another equation

Remove the coefficient of x^2 and divide the coefficient of x by the same. Again, we're going to focus only on what's inside the brackets after this step. 

Find b

Find C

And you're done!

Try a few more questions to see if you understand it. If you have any questions, inline comment on the respective line, and we'll get back to you as soon as possible.