yeah taran is rite...........
or if u can remeber this small formula..then do it
cosA.cos2A.cos4A...........cos2n-1A=(sin2nA)/(2nsinA)
2 Answers
Tarun Kumar Yadav
·Jul 7 '09 at 21:03
multiply and divide the given expression by 2sin(pi/7) and use it to convert to double angles
eureka123
·Jul 7 '09 at 23:19