Question

1) If B=15° then prove that 4sin2B.cos4B. Sin6B=1​

Answer 1

Answer:

given : B =15

To prove : 4sin2B.cos4B. Sin6B=1​

Lhs = 4sin2B.cos4B. Sin6B

      = 4 x sin x 2 x 15 x cos x 4 x 15 x sin x 6 x 15 [ I have used 'x' for                     .                                                                                 multiplication sign]

      = 4sin30 x cos60 x sin 90

   [ We know that sin30 = 1/2, cos60 = 1/2, sin90 = 1]

     = 4 x 1/2 x 1/2 x 1

     = 4/4 = 1 = Rhs

     Hence proved

Hope this helps :)