Solve for m
m\in \begin{bmatrix}-\frac{13}{3},1\end{bmatrix}
Share
Copied to clipboard
36\left(\sqrt{3}\right)^{2}m^{2}+120\sqrt{3}m\sqrt{3}+100\left(\sqrt{3}\right)^{2}-4\times 12\left(3m^{2}+10m+3\right)\geq 0
Use binomial theorem \left(a+b\right)^{2}=a^{2}+2ab+b^{2} to expand \left(6\sqrt{3}m+10\sqrt{3}\right)^{2}.
36\left(\sqrt{3}\right)^{2}m^{2}+120\times 3m+100\left(\sqrt{3}\right)^{2}-4\times 12\left(3m^{2}+10m+3\right)\geq 0
Multiply \sqrt{3} and \sqrt{3} to get 3.
36\times 3m^{2}+120\times 3m+100\left(\sqrt{3}\right)^{2}-4\times 12\left(3m^{2}+10m+3\right)\geq 0
The square of \sqrt{3} is 3.
108m^{2}+120\times 3m+100\left(\sqrt{3}\right)^{2}-4\times 12\left(3m^{2}+10m+3\right)\geq 0
Multiply 36 and 3 to get 108.
108m^{2}+360m+100\left(\sqrt{3}\right)^{2}-4\times 12\left(3m^{2}+10m+3\right)\geq 0
Multiply 120 and 3 to get 360.
108m^{2}+360m+100\times 3-4\times 12\left(3m^{2}+10m+3\right)\geq 0
The square of \sqrt{3} is 3.
108m^{2}+360m+300-4\times 12\left(3m^{2}+10m+3\right)\geq 0
Multiply 100 and 3 to get 300.
108m^{2}+360m+300-48\left(3m^{2}+10m+3\right)\geq 0
Multiply 4 and 12 to get 48.
108m^{2}+360m+300-144m^{2}-480m-144\geq 0
Use the distributive property to multiply -48 by 3m^{2}+10m+3.
-36m^{2}+360m+300-480m-144\geq 0
Combine 108m^{2} and -144m^{2} to get -36m^{2}.
-36m^{2}-120m+300-144\geq 0
Combine 360m and -480m to get -120m.
-36m^{2}-120m+156\geq 0
Subtract 144 from 300 to get 156.
36m^{2}+120m-156\leq 0
Multiply the inequality by -1 to make the coefficient of the highest power in -36m^{2}-120m+156 positive. Since -1 is negative, the inequality direction is changed.
36m^{2}+120m-156=0
To solve the inequality, factor the left hand side. 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.
m=\frac{-120±\sqrt{120^{2}-4\times 36\left(-156\right)}}{2\times 36}
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 36 for a, 120 for b, and -156 for c in the quadratic formula.
m=\frac{-120±192}{72}
Do the calculations.
m=1 m=-\frac{13}{3}
Solve the equation m=\frac{-120±192}{72} when ± is plus and when ± is minus.
36\left(m-1\right)\left(m+\frac{13}{3}\right)\leq 0
Rewrite the inequality by using the obtained solutions.
m-1\geq 0 m+\frac{13}{3}\leq 0
For the product to be ≤0, one of the values m-1 and m+\frac{13}{3} has to be ≥0 and the other has to be ≤0. Consider the case when m-1\geq 0 and m+\frac{13}{3}\leq 0.
m\in \emptyset
This is false for any m.
m+\frac{13}{3}\geq 0 m-1\leq 0
Consider the case when m-1\leq 0 and m+\frac{13}{3}\geq 0.
m\in \begin{bmatrix}-\frac{13}{3},1\end{bmatrix}
The solution satisfying both inequalities is m\in \left[-\frac{13}{3},1\right].
m\in \begin{bmatrix}-\frac{13}{3},1\end{bmatrix}
The final solution is the union of the obtained 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}