Could someone PLEASE help me with these!

1. Verify the identity: (sinx-2+1/sinx)/(sinx-1/sinx)=sinx-1/sinx+1

2.Verify the identity: (1/1-cosx)-(cosx/1+cosx)=2csc(squared)x-1

3.Verify the identity: 2cos4xsin2x=2sin3xcos3x-2cosxsinx

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- April 6th 2008, 01:35 PMkelsey3Trigonometric Identities
Could someone PLEASE help me with these!

1. Verify the identity: (sinx-2+1/sinx)/(sinx-1/sinx)=sinx-1/sinx+1

2.Verify the identity: (1/1-cosx)-(cosx/1+cosx)=2csc(squared)x-1

3.Verify the identity: 2cos4xsin2x=2sin3xcos3x-2cosxsinx - April 6th 2008, 01:45 PMMathstud28Ok
here is what you have ..multiply top and bottom by to get which simplifies to ..and by cancelling the common factor of you get what you want

- April 6th 2008, 01:45 PMa tutor

Working on the LHS

Multiply top and bottom by sinx and then factorise. - April 6th 2008, 01:51 PMMathstud28For the secodn one
which then by combining the fraction gives you ...the top simplifies to by manipulating the pythagorean identity..now seperating that gives what you wnat