Solve for x
x=-\frac{3}{5}=-0.6
Graph
Share
Copied to clipboard
3\sqrt{1-x^{2}}=-4x
Subtract 4x from both sides of the equation.
\left(3\sqrt{1-x^{2}}\right)^{2}=\left(-4x\right)^{2}
Square both sides of the equation.
3^{2}\left(\sqrt{1-x^{2}}\right)^{2}=\left(-4x\right)^{2}
Expand \left(3\sqrt{1-x^{2}}\right)^{2}.
9\left(\sqrt{1-x^{2}}\right)^{2}=\left(-4x\right)^{2}
Calculate 3 to the power of 2 and get 9.
9\left(1-x^{2}\right)=\left(-4x\right)^{2}
Calculate \sqrt{1-x^{2}} to the power of 2 and get 1-x^{2}.
9-9x^{2}=\left(-4x\right)^{2}
Use the distributive property to multiply 9 by 1-x^{2}.
9-9x^{2}=\left(-4\right)^{2}x^{2}
Expand \left(-4x\right)^{2}.
9-9x^{2}=16x^{2}
Calculate -4 to the power of 2 and get 16.
9-9x^{2}-16x^{2}=0
Subtract 16x^{2} from both sides.
9-25x^{2}=0
Combine -9x^{2} and -16x^{2} to get -25x^{2}.
-25x^{2}=-9
Subtract 9 from both sides. Anything subtracted from zero gives its negation.
x^{2}=\frac{-9}{-25}
Divide both sides by -25.
x^{2}=\frac{9}{25}
Fraction \frac{-9}{-25} can be simplified to \frac{9}{25} by removing the negative sign from both the numerator and the denominator.
x=\frac{3}{5} x=-\frac{3}{5}
Take the square root of both sides of the equation.
4\times \frac{3}{5}+3\sqrt{1-\left(\frac{3}{5}\right)^{2}}=0
Substitute \frac{3}{5} for x in the equation 4x+3\sqrt{1-x^{2}}=0.
\frac{24}{5}=0
Simplify. The value x=\frac{3}{5} does not satisfy the equation.
4\left(-\frac{3}{5}\right)+3\sqrt{1-\left(-\frac{3}{5}\right)^{2}}=0
Substitute -\frac{3}{5} for x in the equation 4x+3\sqrt{1-x^{2}}=0.
0=0
Simplify. The value x=-\frac{3}{5} satisfies the equation.
x=-\frac{3}{5}
Equation 3\sqrt{1-x^{2}}=-4x has a unique solution.
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}