Factor
-2\left(b-\frac{3-\sqrt{13}}{2}\right)\left(b-\frac{\sqrt{13}+3}{2}\right)
Evaluate
2+6b-2b^{2}
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-2b^{2}+6b+2=0
Quadratic polynomial can be factored using the transformation ax^{2}+bx+c=a\left(x-x_{1}\right)\left(x-x_{2}\right), where x_{1} and x_{2} are the solutions of the quadratic equation ax^{2}+bx+c=0.
b=\frac{-6±\sqrt{6^{2}-4\left(-2\right)\times 2}}{2\left(-2\right)}
All equations of the form ax^{2}+bx+c=0 can be solved using the quadratic formula: \frac{-b±\sqrt{b^{2}-4ac}}{2a}. The quadratic formula gives two solutions, one when ± is addition and one when it is subtraction.
b=\frac{-6±\sqrt{36-4\left(-2\right)\times 2}}{2\left(-2\right)}
Square 6.
b=\frac{-6±\sqrt{36+8\times 2}}{2\left(-2\right)}
Multiply -4 times -2.
b=\frac{-6±\sqrt{36+16}}{2\left(-2\right)}
Multiply 8 times 2.
b=\frac{-6±\sqrt{52}}{2\left(-2\right)}
Add 36 to 16.
b=\frac{-6±2\sqrt{13}}{2\left(-2\right)}
Take the square root of 52.
b=\frac{-6±2\sqrt{13}}{-4}
Multiply 2 times -2.
b=\frac{2\sqrt{13}-6}{-4}
Now solve the equation b=\frac{-6±2\sqrt{13}}{-4} when ± is plus. Add -6 to 2\sqrt{13}.
b=\frac{3-\sqrt{13}}{2}
Divide -6+2\sqrt{13} by -4.
b=\frac{-2\sqrt{13}-6}{-4}
Now solve the equation b=\frac{-6±2\sqrt{13}}{-4} when ± is minus. Subtract 2\sqrt{13} from -6.
b=\frac{\sqrt{13}+3}{2}
Divide -6-2\sqrt{13} by -4.
-2b^{2}+6b+2=-2\left(b-\frac{3-\sqrt{13}}{2}\right)\left(b-\frac{\sqrt{13}+3}{2}\right)
Factor the original expression using ax^{2}+bx+c=a\left(x-x_{1}\right)\left(x-x_{2}\right). Substitute \frac{3-\sqrt{13}}{2} for x_{1} and \frac{3+\sqrt{13}}{2} for x_{2}.
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}