Solve for x (complex solution)
x=-\sqrt{2}i\approx -0-1.414213562i
x=\sqrt{2}i\approx 1.414213562i
Graph
Share
Copied to clipboard
-6-2x^{2}-6=-8
Combine 4x and -4x to get 0.
-12-2x^{2}=-8
Subtract 6 from -6 to get -12.
-2x^{2}=-8+12
Add 12 to both sides.
-2x^{2}=4
Add -8 and 12 to get 4.
x^{2}=\frac{4}{-2}
Divide both sides by -2.
x^{2}=-2
Divide 4 by -2 to get -2.
x=\sqrt{2}i x=-\sqrt{2}i
The equation is now solved.
-6-2x^{2}-6=-8
Combine 4x and -4x to get 0.
-12-2x^{2}=-8
Subtract 6 from -6 to get -12.
-12-2x^{2}+8=0
Add 8 to both sides.
-4-2x^{2}=0
Add -12 and 8 to get -4.
-2x^{2}-4=0
Quadratic equations like this one, with an x^{2} term but no x term, can still be solved using the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}, once they are put in standard form: ax^{2}+bx+c=0.
x=\frac{0±\sqrt{0^{2}-4\left(-2\right)\left(-4\right)}}{2\left(-2\right)}
This equation is in standard form: ax^{2}+bx+c=0. Substitute -2 for a, 0 for b, and -4 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{0±\sqrt{-4\left(-2\right)\left(-4\right)}}{2\left(-2\right)}
Square 0.
x=\frac{0±\sqrt{8\left(-4\right)}}{2\left(-2\right)}
Multiply -4 times -2.
x=\frac{0±\sqrt{-32}}{2\left(-2\right)}
Multiply 8 times -4.
x=\frac{0±4\sqrt{2}i}{2\left(-2\right)}
Take the square root of -32.
x=\frac{0±4\sqrt{2}i}{-4}
Multiply 2 times -2.
x=-\sqrt{2}i
Now solve the equation x=\frac{0±4\sqrt{2}i}{-4} when ± is plus.
x=\sqrt{2}i
Now solve the equation x=\frac{0±4\sqrt{2}i}{-4} when ± is minus.
x=-\sqrt{2}i x=\sqrt{2}i
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}