Question

prove this and I will mark you brainliest​

Answer 1

Answer:

Step-by-step explanation:sin(3*30)=3sin(30)-4sin^3(30)

sin(90)=3sin(30)-4sin^3(30)

1=3*1/2-4*(1/2)^3

1=3/2-4/8

1=3/2-1/2

1=3-1/2

1=2/2

1=1

Hence verified

Answer 2

Answer:

To prove:-sin3x=3sinx - 4 sin^3 x

Where, x=30°

putting x=30, we get

Sin3(30)=3sin(30)-4sin^3 (30)

Sin 30=1/2

Therefore,

Sin90=3sin30-4sin^3 (30)

1=3/2 - 4*1/8

=>1=3/2 - 1/2

=>1=2/2

=>1=1

Therefore, RHS=LHS

Hence, proved

Hope this will help you