Question

solve this question...
don't copy from internet please​

Answer 1

Step-by-step explanation:

lets take sin(Ф)=3/5 , then sin-1(3/5)= Ф

2(Ф)= sin-1( sin (2Ф))                            [sin(2Ф)=2sin(Ф)cos(Ф)]

=sin-1(2sin(Ф)cos(Ф))

in a right angle triangle with sides 3 and 5 , third side is 4

so cos(Ф)=4/5

there fore,    sin-1(2sin(Ф)cos(Ф))= sin-1(2×3/5×4/5)

                    = sin-1(24/25)=2Ф

in triangle with sides 24 and 25 the third side is 7 ,

so tan(2Ф)=24/7,

and 2Ф= tan-1(tan(2Ф))

=tan-1(24/7) hence proved