Posted by **Dizzytrig** on Tuesday, July 22, 2008 at 11:09am.

how do you veriy

tan x + Cot y

-------------- = tan y + cot x

1-tan x cot y

sin^4x + cos^4x = 1- 2cos^2x + 2cos^4

- verifying identities -
**Damon**, Tuesday, July 22, 2008 at 4:57pm
I get on the right:

sin y / cos y + cos x / sin x

(sin x sin y + cos x cos y) / sin x cos y

sin x sin y/cos x + 1 cos y

----------------------------

sin x cos y/cos x

tan x sin y + cos y

---------------------

tan x cos y

tan x sin y/sin y + cos y/sin y

--------------------------------

tan x cos y/sin y

tan x + cot y

---------------

tan x cot y

- verifying identities -
**Damon**, Tuesday, July 22, 2008 at 5:00pm
sin^4x + cos^4x = 1- 2cos^2x + 2cos^4 this is not complete, assume you mean

2 cos^4 x at the end

sin^4 x = sin^2 x * sin^2 x

=(1 - cos^2 x)(1 - cos^2 x)

= well I guess that gives it away

## Answer this Question

## Related Questions

- Trigonometry - Please review and tell me if i did something wrong. Find the ...
- Math - Trig - I'm trying to verify these trigonometric identities. 1. 1 / [sec(x...
- trigonometry repost - Reduce (csc^2 x - sec^2 X) to an expression containing ...
- precalculus - For each of the following determine whether or not it is an ...
- trig - I do not understand these problems. :S I'd really appreciate the help. ...
- Pre Cal - could someone please tell me what the other angle identity of tan is? ...
- math - how do I simplify these? 1. (Cot/1-tan) + (Tan/1-Cot) - Tan - Cot 2. (1+...
- verifying trigonometric identities - How do I do these problems? Verify the ...
- TRIG.............. - Q.1 Prove the following identities:- (i) tan^3x/1+tan^2x + ...
- TRIGONOMETRY *(MATHS) - Q.1 Prove the following identities:- (i) tan^3x/1+tan^2x...