Solving Separable Equations: How to Solve for Y in Terms of X

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Ok, I'm having trouble with the last part of this problem. After solving for the constant C, I get:
y^2 - 2y = x^3 + 2x^2 +2x + 3

My question is, how do I solve this in terms of Y? The only instruction my book gives me is "To obtain the solution explicitly we must solve for y in terms of x. This is a simple matter in this case since the equation is quadratic in y" and then they jump to the solution:
y = 1 +/- sqrt(x^3 + 2x^2 +2x + 4)
 
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Well you said it yourself: it's a quadratic in terms of y.

Do you know how to solve quadratic equations?
 
dav2008 said:
Well you said it yourself: it's a quadratic in terms of y.

Do you know how to solve quadratic equations?


So would the expression x^3 + 2x^2 +2x + 3 be treated as the 'c' value in the quadratic eq?
 
Yep.

Remember that the quadratic equation let's you solve for a certain variable (we'll call it w here) when you have an equation in the form of aw^2+bw+c=0
 
Alright I got it, thanks a lot
 
davegillmour said:
So would the expression x^3 + 2x^2 +2x + 3 be treated as the 'c' value in the quadratic eq?

Actually, no. Since your equation is y^2 - 2y = x^3 + 2x^2 +2x + 3
and the quadratic is normally written ay^2+ by+ c= 0,
c= -x^3- 2x^2- 2x- 3.
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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