At all points on a certan curve, y'' = 2x. The point (3,6) belongs to the curve andits tangent at this point is inclined at 45 degrees to the X-axis.Find the equation of the curve.

How exactly do I use the bold part for this problem? I've found y' = x^2 + c...

Oh, and is the answer actually y = x^2 - 5x + 12 (txtbk answer) cause it doesn't look right to me.