Trig function help

  • #1
thanks
 
Last edited:

Answers and Replies

  • #2
Can you give the entire problem?
 
  • #4
What is the question? What are you asked to find?
 
  • #6
What is x supposed to be? Is the given problem in terms of t? Are you trying to solve for t and then plug that value in for x?
 
  • #7
oh my bad its cos2t

its basically asking you to use the double angle formula
but im not sure how to find those values
 
  • #8
If you're simply trying to find t, then use cot = 1/tan... If you have a value for t why do you need to use the double angle identities?
 
  • #9
to find what cos2t is ....

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
Are you forbidden from using a calculator?
 
  • #11
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
Well that may have been useful information at the start...

you have cot = -5/4, find what tan is then recall tan = sin/cos ... or recall cot = cos/sin...
 
  • #13
well i worked it out and i believe i got the answer to be 9/41
 

Related Threads on Trig function help

  • Last Post
Replies
5
Views
604
  • Last Post
Replies
2
Views
3K
  • Last Post
Replies
4
Views
1K
  • Last Post
Replies
3
Views
1K
  • Last Post
Replies
1
Views
2K
  • Last Post
Replies
5
Views
8K
  • Last Post
Replies
6
Views
2K
  • Last Post
Replies
10
Views
5K
  • Last Post
Replies
7
Views
2K
Top