Kenneth S. answered • 09/14/17
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sine negative, cosine positive, quadrant IV
θ = arccos(9/13) = 46.19 degrees, IN FIRSTQUADRANT, so θ =360-46.19 = 313.81 deg.
Kenneth S.
all of this kind of problems begin by doing the INVERSE TANGENT
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09/14/17
Kenneth S.
;;;sorry, comment chopped off...once you have the calculator answer, you must CORRECT for quadrant, if needed.
But in the case of arctan, your answer will always be a negative angle (quadrant IV) when the argument is negative.
So in this case, just add 360 degrees to the answer, and now that angle is positive &in quadrant IV.
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09/14/17
Danish K.
can you help me with this one too?
09/14/17