Solve for x
x=\sqrt{2}\approx 1.414213562
x=-\sqrt{2}\approx -1.414213562
Graph
Share
Copied to clipboard
0.25x^{2}=1-\frac{1}{2}
Subtract \frac{1}{2} from both sides.
0.25x^{2}=\frac{1}{2}
Subtract \frac{1}{2} from 1 to get \frac{1}{2}.
x^{2}=\frac{\frac{1}{2}}{0.25}
Divide both sides by 0.25.
x^{2}=\frac{1}{2\times 0.25}
Express \frac{\frac{1}{2}}{0.25} as a single fraction.
x^{2}=\frac{1}{0.5}
Multiply 2 and 0.25 to get 0.5.
x^{2}=\frac{10}{5}
Expand \frac{1}{0.5} by multiplying both numerator and the denominator by 10.
x^{2}=2
Divide 10 by 5 to get 2.
x=\sqrt{2} x=-\sqrt{2}
Take the square root of both sides of the equation.
\frac{1}{2}+0.25x^{2}-1=0
Subtract 1 from both sides.
-\frac{1}{2}+0.25x^{2}=0
Subtract 1 from \frac{1}{2} to get -\frac{1}{2}.
0.25x^{2}-\frac{1}{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.
x=\frac{0±\sqrt{0^{2}-4\times 0.25\left(-\frac{1}{2}\right)}}{2\times 0.25}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 0.25 for a, 0 for b, and -\frac{1}{2} for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{0±\sqrt{-4\times 0.25\left(-\frac{1}{2}\right)}}{2\times 0.25}
Square 0.
x=\frac{0±\sqrt{-\left(-\frac{1}{2}\right)}}{2\times 0.25}
Multiply -4 times 0.25.
x=\frac{0±\sqrt{\frac{1}{2}}}{2\times 0.25}
Multiply -1 times -\frac{1}{2}.
x=\frac{0±\frac{\sqrt{2}}{2}}{2\times 0.25}
Take the square root of \frac{1}{2}.
x=\frac{0±\frac{\sqrt{2}}{2}}{0.5}
Multiply 2 times 0.25.
x=\sqrt{2}
Now solve the equation x=\frac{0±\frac{\sqrt{2}}{2}}{0.5} when ± is plus.
x=-\sqrt{2}
Now solve the equation x=\frac{0±\frac{\sqrt{2}}{2}}{0.5} when ± is minus.
x=\sqrt{2} x=-\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}