SOLUTION: Hi. How do I prove that this is an identity?? I really don't get how this works...
(1-3cosTheta - 4cos^2 Theta)/ sin^2 Theta = (1-4cosTheta)/1-cosTheta
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-> SOLUTION: Hi. How do I prove that this is an identity?? I really don't get how this works...
(1-3cosTheta - 4cos^2 Theta)/ sin^2 Theta = (1-4cosTheta)/1-cosTheta
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Oh, and if you can, please explain how you arrived at the answer as well. I really don't get how our teacher explains this, you see. Thanks a bunch to those who answer! Answer by AnlytcPhil(1807) (Show Source):
The trick is that if you see any of these:
, , , , you can change them to either or ,
which are identities for or respectively, by multiplying and
dividing by the conjugate. There is one of these on the bottom of the right
side, so start with the right side and do just that:
=
=
=
=
=
Edwin
