Question

Perform the subtraction and then use fundamental identities to simplify the following.

1/(sec x +) - 1/ (sec x -1)
AND
tan x - sec 2x/tanx

Answer 1

\[1\div \sec x + 1 - 1\div \sec x-1\]
I screwed up the first problem.

Answer 2

1 1
----- - -----
secx + 1 secx - 1

secx - 1 - (secx + 1)
= -------------------
sec^2 x - 1

-2
= -------------
tan^2 x

Answer 3

is second part

tan x - sec 2x
-------
tan x ?

Answer 4

No it's not. secant squared x.

Answer 5

tan x - sec^2 x
------
tan x

tan^2 x - sec^2
= --------------
tan x

= tan^2 x - ( 1 + tan^2 x)
---------------
tan x

= -1
---- = - cot x
tanx

Answer 6

Now how would I do that? Is there a chart or something with all these things that says so and so is equal to something?

Answer 7

these are trigonometrical identities
do google search - they should be on wikipoedia also)

examples are
sec^2x = 1 + tan^2x (the one i used above)
sin^2x + cos^2x = 1
cosec^2 x = 1 + cot^2 x

tan x = sin x / cos x

- and quite a few more

Answer 8

Damn man I gotta memorize all this junk alright I'll do my best.

Answer 9

yea - i'm afraid so