Question

If x=-1/2 is a root of the quadratic equation 3x2 + 2kx+3= 0, find the
value of k. ​

Answer 1

Answer:

$\underline{\purple{\ddot{\MasterRohith}}}$

Given:-

• If x=-1/2 is a root of the quadratic equation 3x^2+2kx+3=0

To find :-

• The value of k .

Explanation :-

• 3x^2+2kx+3
• 3 (-1/2)^2+2k (-1/2)+3
• 2/4-k+3=0
• k=3/4 +3
• k= 3+12/4
• k=15/4.
• k=3.75.

Therefore ,

• The value of k is 3.75.

Hope it helps u mate .

Thank you .

Answer 2

$\underline{\large{ \sf {GIVEN : }}}$

⟶ $\bf \: x=-\frac{1}{2}$ is a solution of the quadratic equation $\sf 3x^2+2kx+3=0$

$\underline{ \large{\sf {TO\: FIND : }}}$

$\longrightarrow \sf \: Value \: of \: K = \: ?$

$\underline{ \large{\sf {SOLUTION :} }}$

⟶ To get the value of k substitute the value of x in the equation..

$\longrightarrow \: \rm 3x^2+2kx+3=0$

$\rm \longrightarrow\: 3\bigg(-\dfrac{1}{2}\bigg)^2+2k\bigg(-\dfrac{1}{2}\bigg)+3=0$

$\rm \longrightarrow\: 3\bigg(\dfrac{1}{4}\bigg)-k+3=0$

$\rm \longrightarrow\: \dfrac{3}{4}-k+3=0$

$\rm \longrightarrow\: k=\dfrac{3}{4}+3$

$\rm \longrightarrow\: k=\dfrac{3+12}{4}$

$\rm \longrightarrow\: k=\dfrac{15}{4}$

$\rm \longrightarrow\: {k=3.75}$

Therefore,

$\rm \longrightarrow\:\underline{\boxed{\red{\rm Value\:of \: k = \dfrac{15}{4} \: or\: {3.75}} }}$