Question

What signs are sin(100°) and tan(100°)?

A)sin(100°) >0 and tan (100°) < 0
B) they both positive
c) sin(100°) < 0 and tan (100°) > 0
d) they both negative​

Answer 1

A)sin(100°) >0 and tan (100°) < 0

Explanation:

You want to know the signs of sin(100°) and tan(100°).

Quadrant

100° is an angle in the 2nd quadrant, where angles between 90° and 180° lie.

In that quadrant, the sine function is positive, and the cosine function is negative. The tangent is the ratio of sine to cosine, so the tangent is negative in the 2nd quadrant.

• sin(100°) > 0
• tan(100°) < 0

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Additional comment

Of course, your calculator can help you figure this out. Be sure it is in degrees mode.

The second attachment shows you sine is positive above the x-axis; cosine is positive to the right of the y-axis. Everything else derives from this.