Evaluate
\frac{5-\sqrt{5}}{2}\approx 1.381966011
Factor
\frac{\sqrt{5} {(\sqrt{5} - 1)}}{2} = 1.3819660112501053
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-\frac{\left(\sqrt{5}+3\right)^{2}}{2^{2}}+2\times \frac{\sqrt{5}+3}{2}+3
To raise \frac{\sqrt{5}+3}{2} to a power, raise both numerator and denominator to the power and then divide.
-\frac{\left(\sqrt{5}+3\right)^{2}}{2^{2}}+\sqrt{5}+3+3
Cancel out 2 and 2.
-\frac{\left(\sqrt{5}+3\right)^{2}}{2^{2}}+\sqrt{5}+6
Add 3 and 3 to get 6.
-\frac{\left(\sqrt{5}+3\right)^{2}}{2^{2}}+\frac{\left(\sqrt{5}+6\right)\times 2^{2}}{2^{2}}
To add or subtract expressions, expand them to make their denominators the same. Multiply \sqrt{5}+6 times \frac{2^{2}}{2^{2}}.
\frac{-\left(\sqrt{5}+3\right)^{2}+\left(\sqrt{5}+6\right)\times 2^{2}}{2^{2}}
Since -\frac{\left(\sqrt{5}+3\right)^{2}}{2^{2}} and \frac{\left(\sqrt{5}+6\right)\times 2^{2}}{2^{2}} have the same denominator, add them by adding their numerators.
-\frac{\left(\sqrt{5}\right)^{2}+6\sqrt{5}+9}{2^{2}}+\sqrt{5}+6
Use binomial theorem \left(a+b\right)^{2}=a^{2}+2ab+b^{2} to expand \left(\sqrt{5}+3\right)^{2}.
-\frac{5+6\sqrt{5}+9}{2^{2}}+\sqrt{5}+6
The square of \sqrt{5} is 5.
-\frac{14+6\sqrt{5}}{2^{2}}+\sqrt{5}+6
Add 5 and 9 to get 14.
-\frac{14+6\sqrt{5}}{4}+\sqrt{5}+6
Calculate 2 to the power of 2 and get 4.
-\frac{14+6\sqrt{5}}{4}+\frac{4\left(\sqrt{5}+6\right)}{4}
To add or subtract expressions, expand them to make their denominators the same. Multiply \sqrt{5}+6 times \frac{4}{4}.
\frac{-\left(14+6\sqrt{5}\right)+4\left(\sqrt{5}+6\right)}{4}
Since -\frac{14+6\sqrt{5}}{4} and \frac{4\left(\sqrt{5}+6\right)}{4} have the same denominator, add them by adding their numerators.
\frac{-14-6\sqrt{5}+4\sqrt{5}+24}{4}
Do the multiplications in -\left(14+6\sqrt{5}\right)+4\left(\sqrt{5}+6\right).
\frac{10-2\sqrt{5}}{4}
Do the calculations in -14-6\sqrt{5}+4\sqrt{5}+24.
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}