Cos, Tan, and Csc Problem: Evaluating Trigonometric Functions for a Given Theta

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Homework Help Overview

The discussion revolves around evaluating the cosecant function, csc(theta), given specific values for cosine and tangent. The problem is situated within the context of trigonometric functions and their properties, particularly focusing on the implications of quadrant placement based on the signs of these functions.

Discussion Character

  • Exploratory, Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants explore the relationship between cosine and tangent values to determine the possible quadrants for theta. There is an attempt to identify the correct angle based on the given conditions, and some participants discuss the implications of the unit circle and the CAST rule.

Discussion Status

The discussion includes various interpretations of the problem, with participants providing insights into the quadrant analysis and the relationship between sine, cosine, and tangent. Some guidance is offered regarding the implications of the signs of the trigonometric functions, but no explicit consensus is reached on the final evaluation of csc(theta>.

Contextual Notes

Participants note the constraints of the problem, including the specified values for cosine and tangent, and the multiple-choice format of the answers. There is also mention of the unit circle and the CAST rule as tools for understanding the problem's context.

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doing a problem but can't figure out the answer:


Given the following, evaluate csc(theta):

cos(theta) = 1/2

tan(theta) = negative

a> 2

b> -2(square root of)3/3

c> 2(square root of)3/3

d> -2

any help?
 
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01 said:
doing a problem but can't figure out the answer:


Given the following, evaluate csc(theta):

cos(theta) = 1/2

tan(theta) = negative

a> 2

b> -2(square root of)3/3

c> 2(square root of)3/3

d> -2

any help?

i do not understand the part with the a b c and d in it but i can tel lyou that if you look at your unit circle (CAST) rule then you can fiure out the point where the cos is positive and the tan is negative

if cos theta = 0.5 and tan theta < 0 then theta can onlky lie in the first or fourth quadrant i.e. between 0 and 90 and 270 and 360
or if you care in radians 0 to pi/2 and 3pi/2 and 2pi
 
if the cos(theta) = 1/2, then (theta) = pi/3, or 5pi/3, on the interval [0, 2pi],
since it is given that tan(theta) = sin(theta)/cos(theta) < 0,
sin(theta)/(1/2) = 2sin(theta) < 0 or sin(theta) < 0,
therefore (theta) has to be (5pi/3)
now, csc(theta) = 1/sin(theta) = 1/(-3/(2sqrt[3]) = -2sqrt[3]/3
 
Last edited:
thx for the input, now here's another:

what is the phase shift for 3sin (3x+(pi/2))

a> -pi/6

b> 3

c> pi/2

d> -3pi/2

*the a,b,c,& d are multiple choices on the assignment I'm doing.
 
nevermind, i got it.
 

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