Evaluate
\frac{\sqrt{21}}{7}\approx 0.654653671
Share
Copied to clipboard
\frac{3\sqrt{7}\sqrt{3}}{7\left(\sqrt{3}\right)^{2}}
Rationalize the denominator of \frac{3\sqrt{7}}{7\sqrt{3}} by multiplying numerator and denominator by \sqrt{3}.
\frac{3\sqrt{7}\sqrt{3}}{7\times 3}
The square of \sqrt{3} is 3.
\frac{3\sqrt{21}}{7\times 3}
To multiply \sqrt{7} and \sqrt{3}, multiply the numbers under the square root.
\frac{3\sqrt{21}}{21}
Multiply 7 and 3 to get 21.
\frac{1}{7}\sqrt{21}
Divide 3\sqrt{21} by 21 to get \frac{1}{7}\sqrt{21}.
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}