Evaluate
-\frac{9\sqrt{5}}{5}\approx -4.024922359
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\frac{\sqrt{9}}{\sqrt{20}}\left(-6\right)
Rewrite the square root of the division \sqrt{\frac{9}{20}} as the division of square roots \frac{\sqrt{9}}{\sqrt{20}}.
\frac{3}{\sqrt{20}}\left(-6\right)
Calculate the square root of 9 and get 3.
\frac{3}{2\sqrt{5}}\left(-6\right)
Factor 20=2^{2}\times 5. Rewrite the square root of the product \sqrt{2^{2}\times 5} as the product of square roots \sqrt{2^{2}}\sqrt{5}. Take the square root of 2^{2}.
\frac{3\sqrt{5}}{2\left(\sqrt{5}\right)^{2}}\left(-6\right)
Rationalize the denominator of \frac{3}{2\sqrt{5}} by multiplying numerator and denominator by \sqrt{5}.
\frac{3\sqrt{5}}{2\times 5}\left(-6\right)
The square of \sqrt{5} is 5.
\frac{3\sqrt{5}}{10}\left(-6\right)
Multiply 2 and 5 to get 10.
\frac{-3\sqrt{5}\times 6}{10}
Express \frac{3\sqrt{5}}{10}\left(-6\right) as a single fraction.
\frac{-18\sqrt{5}}{10}
Multiply -3 and 6 to get -18.
-\frac{9}{5}\sqrt{5}
Divide -18\sqrt{5} by 10 to get -\frac{9}{5}\sqrt{5}.
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}