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Mathematics 19 Online
OpenStudy (bloomlocke367):

Help with Pre-Cal?

OpenStudy (jdoe0001):

posting specifics helps

OpenStudy (bloomlocke367):

It says to solve algebraically and confirm graphically, and the first problem is \(v^2-5=8-2v^2\)

OpenStudy (bloomlocke367):

I was getting there, lol XD

OpenStudy (jdoe0001):

\(\bf v^2-5=8-2v^2\implies v^2+2v^2=8+5\implies v=?\)

OpenStudy (triciaal):

put the variables on one side constants on the other keep the balance of the equation

OpenStudy (bloomlocke367):

When I solved aglebraically I got \(v=\sqrt{\frac{13}{3}}\)

OpenStudy (bloomlocke367):

But when I graphed it, I don't think it's right... but I may have made an error. That's why I'm asking for help.

OpenStudy (bloomlocke367):

oops, I meant to say when I graphed it, it didn't match my algebraic solution.

OpenStudy (jdoe0001):

notice, is a quadratic equation, 2nd degree polynomial, thus 2 answers \(\bf v^2-5=8-2v^2\implies v^2+2v^2=8+5\implies v=\pm\sqrt{\cfrac{13}{3}}\)

OpenStudy (bloomlocke367):

I forgot to put that, but I know that. lol

OpenStudy (jdoe0001):

hmmm ok.... so.. whathmm how did you do the graph anyway? just a table of values?

OpenStudy (bloomlocke367):

I set the equations equal to zero

OpenStudy (bloomlocke367):

and used a calculator

OpenStudy (bloomlocke367):

equation**

OpenStudy (jdoe0001):

so.... I'd think... the graph is ok...no?

OpenStudy (bloomlocke367):

obviously, I got a parabola with the y-intercept -13. And my zeroes were \(\pm\)2.082

OpenStudy (bloomlocke367):

Is that correct?

OpenStudy (jdoe0001):

\(\bf \pm\sqrt{\cfrac{13}{3}}=\pm2.08166599946613273528\) so, the zeros look fine

OpenStudy (bloomlocke367):

ohhhh... so I was right, sorry. I was thinking of something else when I graphed it and that was my problem lol

OpenStudy (bloomlocke367):

Thanks *facepalm*

OpenStudy (triciaal):

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