Solve for t
t=2
t=\frac{2}{3}\approx 0.666666667
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-\frac{3}{2}t^{2}+4t=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}. The quadratic formula gives two solutions, one when ± is addition and one when it is subtraction.
-\frac{3}{2}t^{2}+4t-2=2-2
Subtract 2 from both sides of the equation.
-\frac{3}{2}t^{2}+4t-2=0
Subtracting 2 from itself leaves 0.
t=\frac{-4±\sqrt{4^{2}-4\left(-\frac{3}{2}\right)\left(-2\right)}}{2\left(-\frac{3}{2}\right)}
This equation is in standard form: ax^{2}+bx+c=0. Substitute -\frac{3}{2} for a, 4 for b, and -2 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
t=\frac{-4±\sqrt{16-4\left(-\frac{3}{2}\right)\left(-2\right)}}{2\left(-\frac{3}{2}\right)}
Square 4.
t=\frac{-4±\sqrt{16+6\left(-2\right)}}{2\left(-\frac{3}{2}\right)}
Multiply -4 times -\frac{3}{2}.
t=\frac{-4±\sqrt{16-12}}{2\left(-\frac{3}{2}\right)}
Multiply 6 times -2.
t=\frac{-4±\sqrt{4}}{2\left(-\frac{3}{2}\right)}
Add 16 to -12.
t=\frac{-4±2}{2\left(-\frac{3}{2}\right)}
Take the square root of 4.
t=\frac{-4±2}{-3}
Multiply 2 times -\frac{3}{2}.
t=-\frac{2}{-3}
Now solve the equation t=\frac{-4±2}{-3} when ± is plus. Add -4 to 2.
t=\frac{2}{3}
Divide -2 by -3.
t=-\frac{6}{-3}
Now solve the equation t=\frac{-4±2}{-3} when ± is minus. Subtract 2 from -4.
t=2
Divide -6 by -3.
t=\frac{2}{3} t=2
The equation is now solved.
-\frac{3}{2}t^{2}+4t=2
Quadratic equations such as this one can be solved by completing the square. In order to complete the square, the equation must first be in the form x^{2}+bx=c.
\frac{-\frac{3}{2}t^{2}+4t}{-\frac{3}{2}}=\frac{2}{-\frac{3}{2}}
Divide both sides of the equation by -\frac{3}{2}, which is the same as multiplying both sides by the reciprocal of the fraction.
t^{2}+\frac{4}{-\frac{3}{2}}t=\frac{2}{-\frac{3}{2}}
Dividing by -\frac{3}{2} undoes the multiplication by -\frac{3}{2}.
t^{2}-\frac{8}{3}t=\frac{2}{-\frac{3}{2}}
Divide 4 by -\frac{3}{2} by multiplying 4 by the reciprocal of -\frac{3}{2}.
t^{2}-\frac{8}{3}t=-\frac{4}{3}
Divide 2 by -\frac{3}{2} by multiplying 2 by the reciprocal of -\frac{3}{2}.
t^{2}-\frac{8}{3}t+\left(-\frac{4}{3}\right)^{2}=-\frac{4}{3}+\left(-\frac{4}{3}\right)^{2}
Divide -\frac{8}{3}, the coefficient of the x term, by 2 to get -\frac{4}{3}. Then add the square of -\frac{4}{3} to both sides of the equation. This step makes the left hand side of the equation a perfect square.
t^{2}-\frac{8}{3}t+\frac{16}{9}=-\frac{4}{3}+\frac{16}{9}
Square -\frac{4}{3} by squaring both the numerator and the denominator of the fraction.
t^{2}-\frac{8}{3}t+\frac{16}{9}=\frac{4}{9}
Add -\frac{4}{3} to \frac{16}{9} by finding a common denominator and adding the numerators. Then reduce the fraction to lowest terms if possible.
\left(t-\frac{4}{3}\right)^{2}=\frac{4}{9}
Factor t^{2}-\frac{8}{3}t+\frac{16}{9}. In general, when x^{2}+bx+c is a perfect square, it can always be factored as \left(x+\frac{b}{2}\right)^{2}.
\sqrt{\left(t-\frac{4}{3}\right)^{2}}=\sqrt{\frac{4}{9}}
Take the square root of both sides of the equation.
t-\frac{4}{3}=\frac{2}{3} t-\frac{4}{3}=-\frac{2}{3}
Simplify.
t=2 t=\frac{2}{3}
Add \frac{4}{3} to both sides of the equation.
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}