Question

if the roots of the equation 2x^2+8x-m^3=0 are equal then value of m is ?​

Answer 1

Step-by-step explanation:

if roots are equal then sum of the roots are

$2\alpha = \frac{ - b}{a}$

$2\alpha = \frac{ - 8}{2} = - 4$

$\alpha = \frac{ -4 }{2 } = - 2$

so roots are -2 and -2

so put in the place of x to get m

$2 {( -2 )}^{2} + 8( - 2) - {m}^{3} = 0$

$8 - 16 - {m}^{3} = 0$

${m}^{3} = 8 = {2}^{3}$

so m=2