Prove

Asked by  | 16th Sep, 2008, 07:41: PM

Expert Answer:

cos6A-sin6A=(cos2A)3-(sin2A)3=(cos2A-Siin2A)(Cos4A+Sin4A+Cos2ASin2A)

                                                      =cos2A((cos2A+Sin2A)2-sin2Acos2A)=cos2A(1-1/4 sin22A)

Answered by  | 17th Sep, 2008, 11:55: AM

Queries asked on Sunday & after 7pm from Monday to Saturday will be answered after 12pm the next working day.