Question

For what value of k equation 2kxsquare - 40x +25 =0 has equal roots . Find roots also

Answer 1

$2k {x}^{2} - 40x + 25 = 0$

if it has equal roots than,

${b}^{2} - 4ac = 0$

Here

$a = 2k \\ b = 40 \\ c = 25$

then

${40}^{2} - (4 \times 2k \times 25) = 0$

$1600 - 450k = 0 \\ 1600 = 450k \\ \frac{1600}{450} =k$

$3.5 = k$