Solve for $x$: $\sqrt 3 {x^2} - 2\sqrt 2 x - 2\sqrt 3 = 0$
Answer
693.3k+ views
Hint- Here, we will be using a discriminant method to solve the given quadratic equation.
Given, equation is $\sqrt 3 {x^2} - 2\sqrt 2 x - 2\sqrt 3 = 0$
As we know that for any general quadratic equation $a{x^2} + bx + c = 0$, the solution is given as
$x = \dfrac{{ - b \pm \sqrt {{b^2} - 4ac} }}{{2a}}$ where $d = \sqrt {{b^2} - 4ac} $ is the discriminant of the quadratic equation.
On comparing the given quadratic equation with the general quadratic equation, we get
$a = \sqrt 3 $ ,$b = - 2\sqrt 2 $ and $c = - 2\sqrt 3 $
Now substitute these values in the formula, we get
$
x = \dfrac{{ - \left( { - 2\sqrt 2 } \right) \pm \sqrt {{{\left( { - 2\sqrt 2 } \right)}^2} - 4\left( {\sqrt 3 } \right)\left( { - 2\sqrt 3 } \right)} }}{{2\left( {\sqrt 3 } \right)}} = \dfrac{{2\sqrt 2 \pm \sqrt {8 + 24} }}{{2\sqrt 3 }} = \dfrac{{2\sqrt 2 \pm \sqrt {32} }}{{2\sqrt 3 }} \\
\Rightarrow x = = \dfrac{{2\sqrt 2 \pm 4\sqrt 2 }}{{2\sqrt 3 }} = \dfrac{{\sqrt 2 \pm 2\sqrt 2 }}{{\sqrt 3 }} \\
$
$ \Rightarrow {x_1} = \dfrac{{\sqrt 2 + 2\sqrt 2 }}{{\sqrt 3 }} = \dfrac{{3\sqrt 2 }}{{\sqrt 3 }} = \left( {\sqrt 3 } \right)\left( {\sqrt 2 } \right) = \sqrt 6 $ and $ \Rightarrow {x_2} = \dfrac{{\sqrt 2 - 2\sqrt 2 }}{{\sqrt 3 }} = \dfrac{{ - \sqrt 2 }}{{\sqrt 3 }} = - \sqrt {\dfrac{2}{3}} $ .
i.e., The two roots of the given quadratic equation are ${x_1} = \sqrt 6 $ and ${x_2} = - \sqrt {\dfrac{2}{3}} $.
Therefore, the two values of $x$ possible in order to satisfy the given quadratic equations are $\sqrt 6 $ and $ - \sqrt {\dfrac{2}{3}} $.
Note- For any quadratic equation, $a{x^2} + bx + c = 0$, according to the value of $d = \sqrt {{b^2} - 4ac} $ we have three possible cases:
i. If it is positive, then the quadratic equation will have two different real roots.
ii. If it is equal to zero, then the quadratic equation will have real and equal roots.
iii. If it is negative, then the quadratic equation will have two different imaginary roots.
Given, equation is $\sqrt 3 {x^2} - 2\sqrt 2 x - 2\sqrt 3 = 0$
As we know that for any general quadratic equation $a{x^2} + bx + c = 0$, the solution is given as
$x = \dfrac{{ - b \pm \sqrt {{b^2} - 4ac} }}{{2a}}$ where $d = \sqrt {{b^2} - 4ac} $ is the discriminant of the quadratic equation.
On comparing the given quadratic equation with the general quadratic equation, we get
$a = \sqrt 3 $ ,$b = - 2\sqrt 2 $ and $c = - 2\sqrt 3 $
Now substitute these values in the formula, we get
$
x = \dfrac{{ - \left( { - 2\sqrt 2 } \right) \pm \sqrt {{{\left( { - 2\sqrt 2 } \right)}^2} - 4\left( {\sqrt 3 } \right)\left( { - 2\sqrt 3 } \right)} }}{{2\left( {\sqrt 3 } \right)}} = \dfrac{{2\sqrt 2 \pm \sqrt {8 + 24} }}{{2\sqrt 3 }} = \dfrac{{2\sqrt 2 \pm \sqrt {32} }}{{2\sqrt 3 }} \\
\Rightarrow x = = \dfrac{{2\sqrt 2 \pm 4\sqrt 2 }}{{2\sqrt 3 }} = \dfrac{{\sqrt 2 \pm 2\sqrt 2 }}{{\sqrt 3 }} \\
$
$ \Rightarrow {x_1} = \dfrac{{\sqrt 2 + 2\sqrt 2 }}{{\sqrt 3 }} = \dfrac{{3\sqrt 2 }}{{\sqrt 3 }} = \left( {\sqrt 3 } \right)\left( {\sqrt 2 } \right) = \sqrt 6 $ and $ \Rightarrow {x_2} = \dfrac{{\sqrt 2 - 2\sqrt 2 }}{{\sqrt 3 }} = \dfrac{{ - \sqrt 2 }}{{\sqrt 3 }} = - \sqrt {\dfrac{2}{3}} $ .
i.e., The two roots of the given quadratic equation are ${x_1} = \sqrt 6 $ and ${x_2} = - \sqrt {\dfrac{2}{3}} $.
Therefore, the two values of $x$ possible in order to satisfy the given quadratic equations are $\sqrt 6 $ and $ - \sqrt {\dfrac{2}{3}} $.
Note- For any quadratic equation, $a{x^2} + bx + c = 0$, according to the value of $d = \sqrt {{b^2} - 4ac} $ we have three possible cases:
i. If it is positive, then the quadratic equation will have two different real roots.
ii. If it is equal to zero, then the quadratic equation will have real and equal roots.
iii. If it is negative, then the quadratic equation will have two different imaginary roots.
Recently Updated Pages
A Paragraph on Pollution in about 100-150 Words

What is BLO What is the full form of BLO class 8 social science CBSE

10 examples of friction in our daily life

Draw a diagram of nephron and explain its structur class 11 biology CBSE

Write structures of the following compounds i 2 Chloro3methylpentane class 11 chemistry CBSE

XIX+XXX A 49 B 51 C 55 D 44 class 5 maths CBSE

Trending doubts
Explain the Treaty of Vienna of 1815 class 10 social science CBSE

1 GB equals how many MB?

10 examples of evaporation in daily life with explanations

What is the full form of POSCO class 10 social science CBSE

Which is the hottest planet in the Solar system A Earth class 10 social science CBSE

Name any four life processes in living things class 10 biology CBSE

