Posted by PLEASE HELP!!! on Thursday, November 12, 2009 at 7:52pm.
how do you do sinAcosA=cosAcos^3A/sinA

trig  Reiny, Thursday, November 12, 2009 at 9:26pm
divide each term by cosA
sinA = 1  cos^2A/sinA
multiply each term by sinA
sin^2A = sinA  cos^2A
sin^2A = sinA  (1  sin^2A)
1 = sinA
A = 90º or pi/2 radians
or in general:
A = k(90)º or k(pi/2) radians

trig  drwls, Thursday, November 12, 2009 at 10:48pm
A = pi/2 + 2 n pi radians. n is any integer, including zero
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