Solve for σ_x
\sigma _{x}=\frac{\sqrt{178}}{3}\approx 4.447221355
\sigma _{x}=-\frac{\sqrt{178}}{3}\approx -4.447221355
Share
Copied to clipboard
\sigma _{x}^{2}=\left(-2\right)^{2}\times \frac{4}{9}+\left(0\times 0\right)^{2}\times \frac{3}{9}+\left(1\times 9\right)^{2}\times \frac{2}{9}
Subtract 0 from -2 to get -2.
\sigma _{x}^{2}=4\times \frac{4}{9}+\left(0\times 0\right)^{2}\times \frac{3}{9}+\left(1\times 9\right)^{2}\times \frac{2}{9}
Calculate -2 to the power of 2 and get 4.
\sigma _{x}^{2}=\frac{16}{9}+\left(0\times 0\right)^{2}\times \frac{3}{9}+\left(1\times 9\right)^{2}\times \frac{2}{9}
Multiply 4 and \frac{4}{9} to get \frac{16}{9}.
\sigma _{x}^{2}=\frac{16}{9}+0^{2}\times \frac{3}{9}+\left(1\times 9\right)^{2}\times \frac{2}{9}
Multiply 0 and 0 to get 0.
\sigma _{x}^{2}=\frac{16}{9}+0\times \frac{3}{9}+\left(1\times 9\right)^{2}\times \frac{2}{9}
Calculate 0 to the power of 2 and get 0.
\sigma _{x}^{2}=\frac{16}{9}+0\times \frac{1}{3}+\left(1\times 9\right)^{2}\times \frac{2}{9}
Reduce the fraction \frac{3}{9} to lowest terms by extracting and canceling out 3.
\sigma _{x}^{2}=\frac{16}{9}+0+\left(1\times 9\right)^{2}\times \frac{2}{9}
Multiply 0 and \frac{1}{3} to get 0.
\sigma _{x}^{2}=\frac{16}{9}+\left(1\times 9\right)^{2}\times \frac{2}{9}
Add \frac{16}{9} and 0 to get \frac{16}{9}.
\sigma _{x}^{2}=\frac{16}{9}+9^{2}\times \frac{2}{9}
Multiply 1 and 9 to get 9.
\sigma _{x}^{2}=\frac{16}{9}+81\times \frac{2}{9}
Calculate 9 to the power of 2 and get 81.
\sigma _{x}^{2}=\frac{16}{9}+18
Multiply 81 and \frac{2}{9} to get 18.
\sigma _{x}^{2}=\frac{178}{9}
Add \frac{16}{9} and 18 to get \frac{178}{9}.
\sigma _{x}=\frac{\sqrt{178}}{3} \sigma _{x}=-\frac{\sqrt{178}}{3}
Take the square root of both sides of the equation.
\sigma _{x}^{2}=\left(-2\right)^{2}\times \frac{4}{9}+\left(0\times 0\right)^{2}\times \frac{3}{9}+\left(1\times 9\right)^{2}\times \frac{2}{9}
Subtract 0 from -2 to get -2.
\sigma _{x}^{2}=4\times \frac{4}{9}+\left(0\times 0\right)^{2}\times \frac{3}{9}+\left(1\times 9\right)^{2}\times \frac{2}{9}
Calculate -2 to the power of 2 and get 4.
\sigma _{x}^{2}=\frac{16}{9}+\left(0\times 0\right)^{2}\times \frac{3}{9}+\left(1\times 9\right)^{2}\times \frac{2}{9}
Multiply 4 and \frac{4}{9} to get \frac{16}{9}.
\sigma _{x}^{2}=\frac{16}{9}+0^{2}\times \frac{3}{9}+\left(1\times 9\right)^{2}\times \frac{2}{9}
Multiply 0 and 0 to get 0.
\sigma _{x}^{2}=\frac{16}{9}+0\times \frac{3}{9}+\left(1\times 9\right)^{2}\times \frac{2}{9}
Calculate 0 to the power of 2 and get 0.
\sigma _{x}^{2}=\frac{16}{9}+0\times \frac{1}{3}+\left(1\times 9\right)^{2}\times \frac{2}{9}
Reduce the fraction \frac{3}{9} to lowest terms by extracting and canceling out 3.
\sigma _{x}^{2}=\frac{16}{9}+0+\left(1\times 9\right)^{2}\times \frac{2}{9}
Multiply 0 and \frac{1}{3} to get 0.
\sigma _{x}^{2}=\frac{16}{9}+\left(1\times 9\right)^{2}\times \frac{2}{9}
Add \frac{16}{9} and 0 to get \frac{16}{9}.
\sigma _{x}^{2}=\frac{16}{9}+9^{2}\times \frac{2}{9}
Multiply 1 and 9 to get 9.
\sigma _{x}^{2}=\frac{16}{9}+81\times \frac{2}{9}
Calculate 9 to the power of 2 and get 81.
\sigma _{x}^{2}=\frac{16}{9}+18
Multiply 81 and \frac{2}{9} to get 18.
\sigma _{x}^{2}=\frac{178}{9}
Add \frac{16}{9} and 18 to get \frac{178}{9}.
\sigma _{x}^{2}-\frac{178}{9}=0
Subtract \frac{178}{9} from both sides.
\sigma _{x}=\frac{0±\sqrt{0^{2}-4\left(-\frac{178}{9}\right)}}{2}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, 0 for b, and -\frac{178}{9} for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
\sigma _{x}=\frac{0±\sqrt{-4\left(-\frac{178}{9}\right)}}{2}
Square 0.
\sigma _{x}=\frac{0±\sqrt{\frac{712}{9}}}{2}
Multiply -4 times -\frac{178}{9}.
\sigma _{x}=\frac{0±\frac{2\sqrt{178}}{3}}{2}
Take the square root of \frac{712}{9}.
\sigma _{x}=\frac{\sqrt{178}}{3}
Now solve the equation \sigma _{x}=\frac{0±\frac{2\sqrt{178}}{3}}{2} when ± is plus.
\sigma _{x}=-\frac{\sqrt{178}}{3}
Now solve the equation \sigma _{x}=\frac{0±\frac{2\sqrt{178}}{3}}{2} when ± is minus.
\sigma _{x}=\frac{\sqrt{178}}{3} \sigma _{x}=-\frac{\sqrt{178}}{3}
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}