A community for students.
Here's the question you clicked on:
 0 viewing
anonymous
 5 years ago
who knows how to COMPLETE THE SQUARE?!
anonymous
 5 years ago
who knows how to COMPLETE THE SQUARE?!

This Question is Closed

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Me! If you have the quadratic,\[ax^2+bx+c\]factor out the a, and do the following:\[a(x^2+\frac{b}{a}x+\frac{c}{a})=a(x^2+\frac{b}{a}x+(\frac{b/a}{2})^2(\frac{b/a}{2})^2+\frac{c}{a})\]\[=a[(x+\frac{b}{2a})^2+\frac{c}{a}(\frac{b}{2a})^2]\]\[=a(x+\frac{b}{2a})^2+c\frac{b^2}{4a}\]If your quadratic is set to zero (i.e. you're finding the roots), then\[a(x+\frac{b}{2a})^2+c\frac{b^2}{4a}=0\rightarrow (x+\frac{b}{2a})^2=\frac{\frac{b^2}{4a}c}{a}\]Ssquare toot both sides and subtract b/2a to yield x.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0ok so here is my problem... t^2  9t _____?____ i need to first make a completed trinomial and then that equals a binomial squared. can you help me through this?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Maybe in about an hour. I'm running late. It depends on how this site goes with my iPhone too.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0I have your answer  just came out of the shower and did it (I shortened my shower for you!). You have the following setup:\[t^29t+c=(at+b)^2\]Don't get these a, b, c's mixed up with what I wrote above  I just picked some pronumerals. Expand the RHS and compare with the LHS  two polynomials are equal if and only if the coefficients of the respective powers are equal, so\[t^29t+c=a^2t^2+2abt+b^2\]implies\[a^2=1 \rightarrow a=\pm1\]which means for the 't' term,\[2(\pm1)b=9 \rightarrow b={\mp}\frac{9}{2}\](pay attention to the signs here). Therefore,\[c=b^2=\frac{81}{4}\]

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0So your equation is \[t^29t+\frac{81}{4}=({\pm}t{\mp}\frac{9}{2})^2\]

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Let me know how you go.

radar
 5 years ago
Best ResponseYou've already chosen the best response.0ok so here is my problem... t^2  9t _____?____ so you are to choose a number to make the results well it looks like lokisan pretty much took care of it.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0radar? do u think u can help hmoazeb?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0ok thanks i will look at it,
Ask your own question
Sign UpFind more explanations on OpenStudy
Your question is ready. Sign up for free to start getting answers.
spraguer
(Moderator)
5
→ View Detailed Profile
is replying to Can someone tell me what button the professor is hitting...
23
 Teamwork 19 Teammate
 Problem Solving 19 Hero
 Engagement 19 Mad Hatter
 You have blocked this person.
 ✔ You're a fan Checking fan status...
Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.