Mister Exam
Other calculators
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How to use it?
- Equation:
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Equation sin(x)+cos(x)=-1
-
Equation x^2-3*x+3=0
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Equation √(x^2-1)^3=2*x
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Equation 1/(x-3)^2-8/(x-3)+15=0
- Express {x} in terms of y where:
- -11*x+10*y=-9
- -9*x-4*y=-20
- -6*x-12*y=9
- 6*x-2*y=-10
- Derivative of:
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3*x^2-12
- Graphing y =:
- 3*x^2-12
- Factor polynomial:
- 3*x^2-12
-
Identical expressions
- three *x^ two - twelve = zero
- 3 multiply by x squared minus 12 equally 0
- three multiply by x to the power of two minus twelve equally zero
- 3*x2-12=0
- 3*x²-12=0
- 3*x to the power of 2-12=0
- 3x^2-12=0
- 3x2-12=0
- 3*x^2-12=O
-
Similar expressions
- 3*x^2+12=0
3*x^2-12=0 equation
The teacher will be very surprised to see your correct solution 😉
The solution
Detail solution
This equation is of the form
A quadratic equation can be solved
using the discriminant.
The roots of the quadratic equation:
$$x_{1} = \frac{\sqrt{D} - b}{2 a}$$
$$x_{2} = \frac{- \sqrt{D} - b}{2 a}$$
where D = b^2 - 4*a*c - it is the discriminant.
Because
$$a = 3$$
$$b = 0$$
$$c = -12$$
, then
Because D > 0, then the equation has two roots.
or
$$x_{1} = 2$$
$$x_{2} = -2$$
a*x^2 + b*x + c = 0
A quadratic equation can be solved
using the discriminant.
The roots of the quadratic equation:
$$x_{1} = \frac{\sqrt{D} - b}{2 a}$$
$$x_{2} = \frac{- \sqrt{D} - b}{2 a}$$
where D = b^2 - 4*a*c - it is the discriminant.
Because
$$a = 3$$
$$b = 0$$
$$c = -12$$
, then
D = b^2 - 4 * a * c =
(0)^2 - 4 * (3) * (-12) = 144
Because D > 0, then the equation has two roots.
x1 = (-b + sqrt(D)) / (2*a)
x2 = (-b - sqrt(D)) / (2*a)
or
$$x_{1} = 2$$
$$x_{2} = -2$$
Vieta's Theorem
rewrite the equation
$$3 x^{2} - 12 = 0$$
of
$$a x^{2} + b x + c = 0$$
as reduced quadratic equation
$$x^{2} + \frac{b x}{a} + \frac{c}{a} = 0$$
$$x^{2} - 4 = 0$$
$$p x + q + x^{2} = 0$$
where
$$p = \frac{b}{a}$$
$$p = 0$$
$$q = \frac{c}{a}$$
$$q = -4$$
Vieta Formulas
$$x_{1} + x_{2} = - p$$
$$x_{1} x_{2} = q$$
$$x_{1} + x_{2} = 0$$
$$x_{1} x_{2} = -4$$
$$3 x^{2} - 12 = 0$$
of
$$a x^{2} + b x + c = 0$$
as reduced quadratic equation
$$x^{2} + \frac{b x}{a} + \frac{c}{a} = 0$$
$$x^{2} - 4 = 0$$
$$p x + q + x^{2} = 0$$
where
$$p = \frac{b}{a}$$
$$p = 0$$
$$q = \frac{c}{a}$$
$$q = -4$$
Vieta Formulas
$$x_{1} + x_{2} = - p$$
$$x_{1} x_{2} = q$$
$$x_{1} + x_{2} = 0$$
$$x_{1} x_{2} = -4$$
The graph