How do you evaluate sin(-3π/2)?

1 Answer
Alan P.
Dec 17, 2015

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

Explanation:

As an angle -(3pi)/2 is equivalent to pi/2

-(3pi)/2 is 3/4 of a circle in a clockwise direction.
pi/2 is 1/4 of a circle in a counter clockwise direction.

sin(pi/2) =1

If you think in terms of a unit radius circular segment centered on the origin of the Cartesian plane with its base along the positive X-axis, then the inscribed right-angled triangle at pi/2 will have a vertex on the positive Y-axis and both the hypotenuse and opposite side will have a length of 1

Related questions
See all questions in Trigonometric Functions of Any Angle
Impact of this question
4585 views around the world
You can reuse this answer
Creative Commons License