Question

if tan15° and tan30° are roots if x²+bx+c=0 then (b-c)²= ?

Answer 1

Please see the attachment

Answer 2

Since tan 15 and tan 30 r roots of given equation
tan15+tan30=-b
tan15. tan30=c
since we know tan (A+B)=tan A+tan B/1- tan A.tan B
=> tan45=tan 15+tan 30/1- tan 15.tan 30
1= -b/1 - c
1-c= -b
b-c=-1
S.O.B.S.
(b-c)^2=1