When you're doing your homework about completing the square the first few of your homework problems are probably going to look like this. They're going to ask you to make something into a perfect square trinomial and the way you do that is by taking half of this b term, squaring that value, by the way this is equal to 4. So I’m going to do 4² and that’s what’s going to go into my blank. I think that’s it.
I think I have a perfect square trinomial, let me just double check perfect square trinomial means it should look like this, (a+b)² equals a² plus 2ab plus b² let’s make sure that’s the case here. I have x² as my first term so I think a should be equal to x and then I have 16 as my b² value, so b should be equal to 4. I think (x+4)² is equal to this. If you were to go through and Foil it, you would see that indeed that’s correct x² plus 8x plus 16 can be written, rewritten as this perfect square binomial.
So let me just review with you what I did to get that 16. I took half of my b value which was 4 and then I squared it and wrote that here as my constant. That’s a really important process that you are going to be following through with your next homework problems.
Experience the 'A-Ha!' moment with the best teachers
whom we hand-picked for you!
M.A. in Secondary Mathematics, Stanford University B.S., Stanford University
Alissa has a quirky sense of humor and a relatable personality that make it easy for students to pay attention and understand the material. She has all the math tips and tricks students are looking for.
“Your tutorials are good and you have a personality as well. I hope you have more advanced college level stuff, because I like the way you teach.”
“Thanks alot for such great lectures... I never found learning this easier ever before... keep up the great work.... :)”
“You seem so kind, it's awesome. Easier to learn from people who seem to be rooting for ya!' thanks”