SOLUTION: -180 < A < 180 find sinA = -cosA

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Question 1195549: -180 < A < 180 find sinA = -cosA
Found 2 solutions by josgarithmetic, ikleyn:
Answer by josgarithmetic(39630) About Me  (Show Source):
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-180 < A < 180

Find sin(A)=-cos(A)

Answer by ikleyn(52879) About Me  (Show Source):
You can put this solution on YOUR website!
.

Your starting equation is

    sin(A) = -cos(A)   and  you consider it in this diapason  -180° < A < 180°.


Divide both sides of the equation by cos(A).  You will get

    tan(A) = -1   and   -180° < A < 180°.


It has two solutions in the given interval  A = -45° and  A = 135°.    ANSWER

Solved, explained and completed.