Question

if ax²+2x+7 equation's one root is (-2) then what will be the value of (a²)​

Answer 1

Answer:

-7/2

Step-by-step explanation:

put -2 in the eqn ax^2+2x+7=0

4a-2a+7=0

a=-7/2

Answer 2

The value of a² is $\frac{9}{16}$.

Step-by-step explanation:

The quadratic equation is:

ax² + 2x + 7 = 0

One of the roots of the equation is, x = - 2.

This value of x will satisfy the equation, i.e. on substituting x = 0 the equation will result as 0.

Compute the value of a as follows:

                     $ax^{2}+2x+7=0$

$(a\times (-2)^{2})+(2\times -2)+7=0$

                         $4a-4+7=0$

                               $4a+3=0$

                                     $4a=-3$

                                       $a=-\frac{3}{4}$

Compute the value of a² as follows:

$a^{2}=(-\frac{3}{4})^{2}=\frac{9}{16}$

Thus, the value of a² is $\frac{9}{16}$.