Question

sin3x =3sinx-4sin square 3 x
if x= 30 then prove that

Answer 1

x = 30

LHS : - sin3(30) = sin90 = 1

RHS : - 3sin(30) - 4{sin3(30)}^2
= 3 × 1/2 - 4(sin90)^2
= 3/2 - 4
= -5/2

LHS =/= RHS

Answer 2

x = 30

LHS : - sin3(30) = sin90 = 1

RHS : - 3sin(30) - 4{sin3(30)}^2

= 3 × 1/2 - 4(sin90)^2

= 3/2 - 4

= -5/2

LHS =/= RHS