Question

if the roots of the eq. x2+px +q=0are tan 30 and tan 15 then find the value of2=p-q is

Answer 1

sum of the roots = -p
$p = \: - (tan30 + tan15)$

$tan45 = \frac{tan30 + tan15}{1 - tan30tan15}$
$p = - (1 - tan30 \: tan15)$
$q = tan30 \: tan15$
$p - q \: = - 1$