Question

show that sin3x+sinx=4 sin x cos^2​

Answer 1

Step-by-step explanation:

we have to proof that

sin3x+sinx=4sinx*cos²x

from L.H.S of above equation

we know that,

=>sin3x=3sinx-4sin³x

so put value of sin3x in question

now,we get

=>3sinx-4sin³x+sinx=>4sinx-4sin³x=>4sinx(1-sin²x)

and we know that

cos²x=1-sin²x

then,

=>4sinx(1-sin²x=>4sinx*cos²x =>R.H.S.

Hence result is proved