Question

if x=30 degree verify sin x = underoot 1-cos2x/2

Answer 1

if x=30 degree
sin 30=1/2
RHS= underoot 1-cos2*30/2
=underoot 1-cos60/2
=underoot (1-1/2)/2
=underoot(1/4)
=1/2=LHS

Answer 2

LHS of eq

sinx

when x=30

sin(30)=1/2

LHS=1/2

RHS of eq

root of(1-cos2x)/2

if x=30

=root of (1-cos60)/2

=root of(1-1/2)/2

=root of(1/2)/2

=root of (1/4)

=1/2

RHS=1/2

RHS=LHS=1/2

hence eq is proved