Why Are My Trig Ratios csc and sec Incorrect for (7π)/4?

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SUMMARY

The discussion centers on the calculation of trigonometric ratios for the angle (7π)/4. The user correctly calculated sin, cos, tan, and cot but miscalculated csc and sec. The correct values are csc = -√2 and sec = √2, derived from the reciprocals of sin and cos, respectively. The confusion arose from improper rationalization of the denominators in the user's initial calculations.

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  • Ability to rationalize denominators in mathematical expressions
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  • Study the unit circle to reinforce understanding of trigonometric ratios
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Homework Statement


The question states to find the primary trig ratios for (7π)/4

Homework Equations

The Attempt at a Solution


I got
sin= (-√2)/2
cos=(√2)/2
tan= -1
csc= 2/(-√2)
sec= 2/(√2)
cot= -1

I got all of them correct except for csc and sec, and I am unsure why the solutions are telling me
csc = -√2
sec = √2
I thought my original answers were correct because csc is reciprocal of sin and sec is reciprocal of cos.
Can someone help me make sense of this?
 
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Write ##2= \sqrt{2}\,\cdot\,\sqrt{2}## and cancel one root factor.
 
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Veronica_Oles said:

Homework Statement


The question states to find the primary trig ratios for (7π)/4

Homework Equations

The Attempt at a Solution


I got
sin= (-√2)/2
cos=(√2)/2
tan= -1
csc= 2/(-√2)
sec= 2/(√2)
cot= -1

I got all of them correct except for csc and sec, and I am unsure why the solutions are telling me
csc = -√2
sec = √2
I thought my original answers were correct because csc is reciprocal of sin and sec is reciprocal of cos.
Can someone help me make sense of this?
Rationalize the denominators.
 

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