Question

If sin(x) =-1/2 and tan(x) is negative what is cos(2x)

Answer 1

Answer:

positive

Step-by-step explanation:

Using the acronym ASTC (all students take calculus), this means that if sin and tan are negative, they must be in the fourth quadrant, which means that cos is positive.

ASTC is an acronym to help students remember which of the three basic trigonometric functions are positive in which quadrants.

A: all

S: sin

T: tan

C: cos

It starts from the first quadrant: all the sin, tan, cos are positive in the first quadrant, only sin is positive in the second quadrant, only tan is positive in the third quadrant, only cos is positive in the fourth quadrant.