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Math Help - Yet another "Verify the trig identity" prob...HELP

  1. #1
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    Yet another "Verify the trig identity" prob...HELP

    Verify the following identity by starting with the left hand side.

    tan^2(x/2+pi/4)=1+sinx/1-sinx.....don't have a "pi" character, hopefully that was understandable. Not quite sure how to start this. Should I just use an addition formula?....or do I need to use a formula to lower the power on the tan^2....????...Loosin' my mind here....

    Thanks for any help.

    ~CC
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  2. #2
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    Using the identity \tan^2{x} = \frac{1-\cos{2x}}{1+\cos{2x}} and \cos{(A\pm B)}=\cos{A}\cos{B} \mp \sin{A}\sin{B}, we can write the LHS as:

    \frac{1-\cos{(x+\frac{\pi}{2})}}{1+\cos{(x+\frac{\pi}{2})}  } = \frac{1+\sin{x}}{1-\sin{x}}
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  3. #3
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    Thank you for the help Chop Suey!

    ~CC
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