Solve for y
y=\sqrt{2}\approx 1.414213562
y=-\sqrt{2}\approx -1.414213562
Graph
Share
Copied to clipboard
-y^{2}=3-5
Subtract 5 from both sides.
-y^{2}=-2
Subtract 5 from 3 to get -2.
y^{2}=\frac{-2}{-1}
Divide both sides by -1.
y^{2}=2
Fraction \frac{-2}{-1} can be simplified to 2 by removing the negative sign from both the numerator and the denominator.
y=\sqrt{2} y=-\sqrt{2}
Take the square root of both sides of the equation.
5-y^{2}-3=0
Subtract 3 from both sides.
2-y^{2}=0
Subtract 3 from 5 to get 2.
-y^{2}+2=0
Quadratic equations like this one, with an x^{2} term but no x term, can still be solved using the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}, once they are put in standard form: ax^{2}+bx+c=0.
y=\frac{0±\sqrt{0^{2}-4\left(-1\right)\times 2}}{2\left(-1\right)}
This equation is in standard form: ax^{2}+bx+c=0. Substitute -1 for a, 0 for b, and 2 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
y=\frac{0±\sqrt{-4\left(-1\right)\times 2}}{2\left(-1\right)}
Square 0.
y=\frac{0±\sqrt{4\times 2}}{2\left(-1\right)}
Multiply -4 times -1.
y=\frac{0±\sqrt{8}}{2\left(-1\right)}
Multiply 4 times 2.
y=\frac{0±2\sqrt{2}}{2\left(-1\right)}
Take the square root of 8.
y=\frac{0±2\sqrt{2}}{-2}
Multiply 2 times -1.
y=-\sqrt{2}
Now solve the equation y=\frac{0±2\sqrt{2}}{-2} when ± is plus.
y=\sqrt{2}
Now solve the equation y=\frac{0±2\sqrt{2}}{-2} when ± is minus.
y=-\sqrt{2} y=\sqrt{2}
The equation is now solved.
Examples
Quadratic equation
{ x } ^ { 2 } - 4 x - 5 = 0
Trigonometry
4 \sin \theta \cos \theta = 2 \sin \theta
Linear equation
y = 3x + 4
Arithmetic
699 * 533
Matrix
\left[ \begin{array} { l l } { 2 } & { 3 } \\ { 5 } & { 4 } \end{array} \right] \left[ \begin{array} { l l l } { 2 } & { 0 } & { 3 } \\ { -1 } & { 1 } & { 5 } \end{array} \right]
Simultaneous equation
\left. \begin{cases} { 8x+2y = 46 } \\ { 7x+3y = 47 } \end{cases} \right.
Differentiation
\frac { d } { d x } \frac { ( 3 x ^ { 2 } - 2 ) } { ( x - 5 ) }
Integration
\int _ { 0 } ^ { 1 } x e ^ { - x ^ { 2 } } d x
Limits
\lim _{x \rightarrow-3} \frac{x^{2}-9}{x^{2}+2 x-3}