Posted by **PLEASE HELP!!!** on Thursday, November 12, 2009 at 7:52pm.

how do you do sinAcosA=cosA-cos^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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