Solve for x (complex solution)
x=-\sqrt{3}i-1\approx -1-1.732050808i
x=2
x=-1+\sqrt{3}i\approx -1+1.732050808i
Solve for x
x=2
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x^{3}-20+12=0
Add 12 to both sides.
x^{3}-8=0
Add -20 and 12 to get -8.
±8,±4,±2,±1
By Rational Root Theorem, all rational roots of a polynomial are in the form \frac{p}{q}, where p divides the constant term -8 and q divides the leading coefficient 1. List all candidates \frac{p}{q}.
x=2
Find one such root by trying out all the integer values, starting from the smallest by absolute value. If no integer roots are found, try out fractions.
x^{2}+2x+4=0
By Factor theorem, x-k is a factor of the polynomial for each root k. Divide x^{3}-8 by x-2 to get x^{2}+2x+4. Solve the equation where the result equals to 0.
x=\frac{-2±\sqrt{2^{2}-4\times 1\times 4}}{2}
All equations of the form ax^{2}+bx+c=0 can be solved using the quadratic formula: \frac{-b±\sqrt{b^{2}-4ac}}{2a}. Substitute 1 for a, 2 for b, and 4 for c in the quadratic formula.
x=\frac{-2±\sqrt{-12}}{2}
Do the calculations.
x=-\sqrt{3}i-1 x=-1+\sqrt{3}i
Solve the equation x^{2}+2x+4=0 when ± is plus and when ± is minus.
x=2 x=-\sqrt{3}i-1 x=-1+\sqrt{3}i
List all found solutions.
x^{3}-20+12=0
Add 12 to both sides.
x^{3}-8=0
Add -20 and 12 to get -8.
±8,±4,±2,±1
By Rational Root Theorem, all rational roots of a polynomial are in the form \frac{p}{q}, where p divides the constant term -8 and q divides the leading coefficient 1. List all candidates \frac{p}{q}.
x=2
Find one such root by trying out all the integer values, starting from the smallest by absolute value. If no integer roots are found, try out fractions.
x^{2}+2x+4=0
By Factor theorem, x-k is a factor of the polynomial for each root k. Divide x^{3}-8 by x-2 to get x^{2}+2x+4. Solve the equation where the result equals to 0.
x=\frac{-2±\sqrt{2^{2}-4\times 1\times 4}}{2}
All equations of the form ax^{2}+bx+c=0 can be solved using the quadratic formula: \frac{-b±\sqrt{b^{2}-4ac}}{2a}. Substitute 1 for a, 2 for b, and 4 for c in the quadratic formula.
x=\frac{-2±\sqrt{-12}}{2}
Do the calculations.
x\in \emptyset
Since the square root of a negative number is not defined in the real field, there are no solutions.
x=2
List all found solutions.
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}