Find the values of P for which the quadratic equation 4x²+px+3=0 , provided that roots are equal or discriminant is zero .
Let us Consider a quadratic equation αx² + βx + c = 0, then nature of roots of quadratic equation depends upon Discriminant (D) of the quadratic equation.
For equal roots
[tex]\quad\green{ \underline { \boxed{ \sf{Discriminant, D = β² - 4αc}}}} [/tex]
So,
[tex]\sf{ β² - 4αc = 0}[/tex]
Here,
Now,
[tex]\begin{gathered}\implies\quad \sf p²- 4 \times 4 \times 3 =0 \end{gathered} [/tex]
[tex]\begin{gathered}\implies\quad \sf p²- 48 =0 \end{gathered} [/tex]
[tex]\begin{gathered}\implies\quad \sf p²=48\end{gathered} [/tex]
[tex]\begin{gathered}\implies\quad \sf p=±\sqrt{48}\end{gathered} [/tex]
[tex]\begin{gathered}\implies\quad \sf p=±\sqrt{2 \times 2 \times 2 \times 2 \times 3} \end{gathered}[/tex]
[tex]\begin{gathered}\implies\quad \sf p=± 2\times 2\sqrt{ 3 }\end{gathered} [/tex]
[tex]\begin{gathered}\implies\quad \boxed{\sf{p=±4\sqrt{ 3 }}}\end{gathered} [/tex]
Thus, the values of P for which the quadratic equation 4x²+px+3=0 are-
4√3 and -4√3.