Using the following equation, find the center and radius of the circle. You must show all work and calculations to receive credit.

x^2 + 4x + y^2 − 6y = −4

Question

Using the following equation, find the center and radius of the circle. You must show all work and calculations to receive credit.

x^2 + 4x + y^2 − 6y = −4

izzybeex2 · Answer

I don't know how to do this. I don't want the answer I just need a little bit of explaining.

welshfella · Answer

you need to complete the square for the terms in x and the terms in y.

izzybeex2 · Answer

Would I combine the similar terms first?

welshfella · Answer

x^2 + 4x  =  (x + 2)^2 -  Z


what would be the value of Z which makes the above an identity

izzybeex2 · Answer

Um. I don't know. I'm sorry this is all very confusing for me.

welshfella · Answer

first thing is to divide coefficient of x by 2
thats where the (x + 2)^2 comes from

If you expand (x +2)^2  you'll see what  Z shloud be

izzybeex2 · Answer

What does Z stand for?

welshfella · Answer

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