सिद्ध कीजिए कि ` sin. pi/10 * cos. pi/5 = 1/4 `

FInd sin(pi/10). cos(pi/5)

Prove that: sin(pi/10). cos(pi/5)=1/4

The numerical value of (where i = sqrt-1 ) (cos pi/10 + i sin pi/10)(cos 2pi/10 + i sin 2pi/10) xx (cos 3pi/10 + i sin 3pi/10) (cos 4pi/10 + i sin 4pi/10) = ..........

sin (pi/2) = 2 sin(pi/4) cos (pi/4)

Find the value of ((1 + sin"" (pi)/(10) + i cos"" (pi)/(10))/(1 + sin"" (pi)/(10) - i cos"" (pi)/(10)))^(10) .

Numerical value of cos ((pi) / (12)) ((sin (5 pi)) / (12) + cos ((pi) / (4))) + sin ((pi) / (12)) (( cos (5 pi)) / (12) -sin ((pi) / (4)))

Find the value of sin^(-1) (sin . (5pi)/8 cos . (pi)/8 - cos . (5pi)/8 sin. (pi)/8)

sin^(-1)(cos(pi/5))

Prove that sin "" (1)/(10) pi cos ""(1)/(5) pi = (1)/(4).

Prove that (i) " tan"^(2) .(pi)/(3) + 2cos^(2) .(pi)/(4)+ 3 sec^(2).(pi)/(6)+ 4 cos^(2).(pi)/(2)=8 (ii) " sin ".(pi)/(6) " cos 0 + sin ".(pi)/(4) " cos " .(pi)(4) + " sin " .(pi)/(3) "cos " .(pi)/(6) =(7)/(4) (iii) " 4sin " (pi)/(6) " sin"^(2) (pi)/(3) + 3 " cos " .(pi)/(3) " tan ".(pi)/(4) = " cosec"^(2).(pi)/(2)=4