Question

Simplify:
(SecX^2-TanX^2)/Cos(-X)
For my lovely @wet and @shelbygt520
That Latex stuff seemed to take too long, so I hope you get that.

Answer 1

For this I got the answer as CosX, but the correct answer is CosX^2.

Answer 2

https://www.youtube.com/watch?v=TfzIObd_7Hw

Answer 3

What the heck did I just watch?

Answer 4

You just watched the answer

Answer 5

ok let me explain it word by word bib help me out here

Answer 6

to all of your problems

Answer 7

But it wasn't the same question O.o

Answer 8

(secx)^2-(tanx)^2
that's definitely your question

Answer 9

oh wait there's a cos(-x)

Answer 10

Oh, you mean without the denominator?

Answer 11

>.>

Answer 12

k imma start first shelbs

Answer 13

kk

Answer 14

Recall the basic trig identity \[\large \sin^2x+\cos^2x = 1\]we can then derive:\[\large \sec^2x= 1+tan^2x \]\[\large \sec^2x-tan^2x= 1 \]

Answer 15

Yeah, those are the Pythogorean Identities.

Answer 16

pls\[\huge \frac{(\sec^2x-\tan^2x)}{\cos(-X)}\]\[\huge (\sec^2x-\tan^2x)=1\]

Answer 17

Holy...

Answer 18

So the Answer is 1/Cos(-X)?

Answer 19

I think there's an identity for the bottom. cos(-x) = cosx

Answer 20

at least that's what it looks like from this http://www.wolframalpha.com/input/?i=cos+-x

Answer 21

OOh yeah i have that identity in my book, so 1/CosX?

Answer 22

aka ?

Answer 23

SecX?

Answer 24

that's the simplest form

Answer 25

Wait, so why did my teacher put a huge red X and tell me the answer is CosX^2?

Answer 26

no clue but bib is correct

Answer 27

I don't think I'm wrong...

Answer 28

I also don't think you're wrong, but i don't understand why the teacher did that

Answer 29

Weird.

Answer 30

even wolfram says it evaluates to secx(sec^2x-tan^2x) = secx

http://www.wolframalpha.com/input/?i=%28SecX%5E2-TanX%5E2%29%2FCos%28-X%29

Answer 31

Go up to your teacher and ask why. He probably made a mistake.

"Everybody makes mistakes" - hannah montana

Answer 32

your teacher may have missed something take it back to her and explain how you got the answer and show her evidence to support it

Answer 33

Okay, again, thank you guys sooooo much!

Answer 34

me and bib here are always here to help! :) bib where are you?! a strip club?! @we

Answer 35

@wet

Answer 36

Okay guys, sorry, I know I'm asking too much, but I just have this last confusing question

Answer 37

woah I don't do that yo. don't sully my name @shelbygt520 bby

Answer 38

you know the drill. new question tag me/her/us

Answer 39

lol