Solving y² - 2y = x³ + 2x² + 2x + 3 for y

[jesuslovesu]

Homework Statement

y^2 - 2y = x^3 + 2x^2 + 2x + 3

Homework Equations

The Attempt at a Solution

Solve for y
How do you solve for y? my book says since that equation is quadratic in y, it can be solved as y = 1 +- sqrt(x^3 + 2x^2 + 2x + 4) but I have no idea how to do that...

all I can do is y(y-2) ...

 

[rock.freak667]

Can you express $y^2-2y$ in the form $a(y+h)^2+k$?

 

[jesuslovesu]

Thanks for your reply
y^2 - 2y - K = 0
-k, -2y
K = x^3 + ...
Unfortunately, i seem unable to do so

 

[jesuslovesu]

Oh wait, I forgot about completing the square, I got it thanks

 

[disregardthat]

You can also use the quadratic formula, might be easier.