How do you evaluate sin((3pi)/2) ?

1 Answer
Alan P.
Jul 30, 2015

sin((3pi)/2) = -1

Explanation:

In standard position, an angle of (3pi)/2 has a hypotenuse which falls along the negative Y-axis.

If a hypotenuse of unit length is swung towards the negative Y-axis, the side opposite the origin approaches -1.
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Since sin(theta) is defined as the ratio of the opposite side to the hypotenuse,
as theta rarr (3pi)/2
color(white)("XXXXXXXX")sin(theta) rarr -1/1

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