Posted by **Kate** on Sunday, July 17, 2011 at 10:29am.

Solve for all possible values of x where O°≤x≤360°.

tan x = -1/√3

cos x = 1/2

- Math -
**MathMate**, Sunday, July 17, 2011 at 1:19pm
Use the CAST rule to determine the sign of the functions cosine and tangent:

C-quad.4, Cosine >0

A-quad.1, All functions >0

S-quad.2, sin>0

T-quad.3, tan>0

From the given values,

cos(θ)>0 and

tan(θ)<0

Only θ in quad.4 will satisfy both conditions.

Therefore find the reference angle (between 0 and 90°)

t=arctan(1/√3), or

t=arccos(1/2)

and obtain

θ=360-t (4th quadrant).

## Answer this Question

## Related Questions

- algebra 1 help please - 4) a student score is 83 and 91 on her first two quizzes...
- PRE - CALCULUS - Eliminate the parameter t. Find a rectangular equation for the ...
- Math - Let sin A = 12/13 with 90º≤A≤180º and tan B = -4/3 with 270...
- Math/Trigonometry - 1. Solve: 2 cos² x - 3 cos x + 1 = 0 for 0 ≤ x < ...
- Trig - Let sin A = 12/13 with 90º≤A≤180º and tan B = -4/3 with 270...
- trig - Let sin A = 12/13 with 90º≤A≤180º and tan B = -4/3 with 270...
- Algebra 2 - Solve. 4a-2≤a+1≤3a+4 4a-2-1≤a+1-1≤3a+4-1 4a-...
- Math/Trigonometry - 1. Solve: 2 cos² x - 3 cos x + 1 = 0 for 0 ≤ x < ...
- Math (Trigonometry) - 1. If sec x + tan x = 3/2 and 0 ≤ x ≤ pi/2 ...
- Trigonometry - IM STUCK ON THESE :( 1. What is the equation for shifting the ...