# Thread: Polar coordinates & systems of equations

1. ## Polar coordinates & systems of equations

I'm studying for a subject matter exam in order to become a certified teacher in Texas. I need help with some of the sample questions. These are not the actual questions that will be on the test.

It's not necessary to be extremely detailed. A quick step-by-step, or how to do it on the calculator, or a summary of what I'm looking for, is usually fine.

Thanks!

Hope I'm posting this in the right place. I'm pretty sure polar coordinates makes this pre-calculus.

2. ## Re: Polar coordinates & systems of equations

Originally Posted by jbwtucker
I'm studying for a subject matter exam in order to become a certified teacher in Texas. I need help with some of the sample questions. These are not the actual questions that will be on the test.

It's not necessary to be extremely detailed. A quick step-by-step, or how to do it on the calculator, or a summary of what I'm looking for, is usually fine.

Thanks!

Hope I'm posting this in the right place. I'm pretty sure polar coordinates makes this pre-calculus.

i don't see why we need to do this using polar coordinates. my solution is:
1) equation of the line shown is $y-x=2$.
2)equation of the circle shown is $x^2+y^2=1$.
you just have to solve the two equations simultaneously. just substitute $y=x+2$ in the second equation and solve the quadratic.

3. ## Re: Polar coordinates & systems of equations

I see. You're right, I guess it just looked like polar coordinates.

So...

x^2 + (x+2)^2 = 1
2x^2 + 4x + 4 = 1
2x^2 + 4x + 3 = 0

Quadratic equation gives x = -1 ± (i√2)/2.

Which is the same as x = -1 ± [(√2)/2]i. One of which is C.

Thank you!