- #1

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thanks

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- Thread starter Eric Manuel
- Start date

- #1

- 7

- 0

thanks

Last edited:

- #2

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Can you give the entire problem?

- #3

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Can you give the entire problem?

all thats given is that

- #4

- 345

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What is the question? What are you asked to find?

- #5

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what is =cos2xWhat is the question? What are you asked to find?

- #6

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- #7

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its basically asking you to use the double angle formula

but im not sure how to find those values

- #8

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- #9

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you can find what tan is from cot

then i drew a triangle and got the hypot to be sqrt(41)

but how do i do that math

formula for cos2t = cos^2(t) - sin^2(t)

- #10

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Are you forbidden from using a calculator?

- #11

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Are you forbidden from using a calculator?

teacher said u can use it

but need to know how to do it without one for test

- #12

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you have cot = -5/4, find what tan is then recall tan = sin/cos ... or recall cot = cos/sin...

- #13

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well i worked it out and i believe i got the answer to be 9/41

- #14

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That's what I'm getting

- #15

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You might find this link useful: http://www.mhhe.com/math/precalc/ba...tt01paga_s/ch06/downloads/pc/ch06section3.pdf

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