# Please show me what I am doing wrong (conic section)

• Aug 23rd 2009, 02:14 AM
bobbyboy1111
Please show me what I am doing wrong (conic section)
1. x^2 + y^2 = 225

y^2 = -x^2 + 225

y = +_SQRT(-x^2 + 225)

Ellipse
• Aug 23rd 2009, 04:17 AM
mr fantastic
Quote:

Originally Posted by bobbyboy1111
1. x^2 + y^2 = 225

y^2 = -x^2 + 225

y = +_SQRT(-x^2 + 225)

Ellipse

I have no idea what your question. But yes, x^2 + y^2 = 225 is an ellipse. In fact, it's a very special ellipse .... its an ellipse whose eccentricity is equal to zero - more commonly known as a circle. In your case the circle has center at (0, 0) and r = 15.
• Aug 23rd 2009, 05:20 AM
bobbyboy1111
Quote:

Originally Posted by mr fantastic
I have no idea what your question. But yes, x^2 + y^2 = 225 is an ellipse. In fact, it's a very special ellipse .... its an ellipse whose eccentricity is equal to zero - more commonly known as a circle. In your case the circle has center at (0, 0) and r = 15.

My teacher said that the following which I wrote above is incorrect. That is my question, why is it incorrect, what did I do wrong? Do you think it could be that I forgot to mention that it is a circle?
• Aug 23rd 2009, 09:11 PM
mr fantastic
Quote:

Originally Posted by bobbyboy1111
My teacher said that the following which I wrote above is incorrect. That is my question, why is it incorrect, what did I do wrong? Do you think it could be that I forgot to mention that it is a circle?

It could be .... I really don't know since you haven't said waht the original question was.

Maybe your equation x^2 + y^2 = 225 is wrong?

Since you haven't posted the actual question you were working on, nor shown any working, and since my crystal ball is currently being serviced, at this point in time nothing further can be said to help you.
• Aug 23rd 2009, 11:24 PM
bobbyboy1111
Quote:

Originally Posted by mr fantastic
It could be .... I really don't know since you haven't said waht the original question was.

Maybe your equation x^2 + y^2 = 225 is wrong?

Since you haven't posted the actual question you were working on, nor shown any working, and since my crystal ball is currently being serviced, at this point in time nothing further can be said to help you.

Crystal ball?(Giggle)