Question

prove this --- sin(1)A - 2sin(3)A/ 2cos(3)A - cosA =tanA {valuse given in ( ) are degree of sin amd cos } ​

Answer 1

Answer:

Step-by-step explanation:

SinA - 2Sin³A / 2Cos³A - CosA

= SinA (1 - 2Sin²A)/ CosA(2Cos²A - 1)

//But Cos2A = Cos²A - Sin²A = 2Cos²A - 1 =  1 - 2Sin²A.

= SinA/CosA[(1 - 2Sin²A)/(2Cos²A - 1)]

= TanA(Cos2A/Cos2A)

= TanA

= R.H.S

Hence Proved.