Hey everyone-
Now I know there are some math geniuses on here, and i need a bit of help. I am good at math, but have gotten a bit rusty at trig identities over the summer. Now I am taking a college math placement test and this problem is driving me crazy! So many time I get so close and keep hitting a block.
If you could show the work that would be great. THANK YOU!
Here it is:
sec^2(x)-sec(x)tan(x)=1/(1+sec(x))
I think your book is wrong:
sec^2(x) - sec(x)tan(x)
= 1/cos^2(x) - sin(x)/cos^2(x)
= (1-sin(x)) / cos^2(x)
= (1-sin(x)) / (1-sin^2(x))
= 1/(1+sin(x))
If you can’t answer the question, you shouldn’t cheat your way through the test. It’s worth being placed in a lower-level class since you’ll need to be absolutely solid on the material before progressing into higher-level classes. You’re going to suffer greatly otherwise…
I’d wager you’re supposed to take the integral of both sides, which would give you (please correct me if I’m wrong, I’m a little rusty):
tan(x) - sec(x) = INTEGRAL(1/(1+sec(x)))
Damn I don’t remember how to take the integral of that…I’m gonna keep what I have there and look at my old notes a sec…
Oh ok, I found it. You get…
tan(x) - sec(x) = x - tan(x/2) + C
(I just kept the C on one side to keep it simpler)
From there I’m not totally sure what to do, lol. I’m rusty on all those rules.
Oh wait…tan(x/2) I found…
tan(x) - sec(x) = x - csc(x) + cot(x) + C
sinx/cosx - 1/cosx = x - 1/sinx + cosx/sinx + C
(sinx - 1)/cosx = x - (1 + cosx)/sinx + C
(sinx-1)/cosx + (1+cosx)/sinx = x+C
Hold on now I need some pen and paper to common denominator that bitch…
K I’m at…
(sin^2(x) - sinx + cos^2(x) + cosx)/cosxsinx = x + C
Which can go to…
(1 + cosx - sinx)/cosxsinx = x + C
Hmm…from here…I’m stuck again, hold on.
Dang I’m stumped at the moment. 
Sorry.
i could do it if i wanted to…
but you are getting along so well, dont give up.
Well I tried a couple different paths from where I’m at but they all seem to dead end.
i didn’t even know that tan was maths related…
shh.
Wow… I do not feel like thinking.
My brain is rotting away over the summer. I’ve had enough trigonometry to last me a lifetime…
Edit: trig is probably the thing in math that I most despise.
Phlegm is right. I hope they’re not asking you to prove that. Are you sure you typed it correctly?
That looks stupidly confusing… But at least I know what the tan, sin and cos are 
what about log?
they come from trees… It could therefor be something to do with roots…
Log is what you ride on a MUni.
Oh for real? And I thought I was making progress… 
Log is also what i used on my school graphics calculator to write such things as: 1.log93d.my.pAn+5 (substitute the ‘n’ for pi symbol)
instead of doing sums like i should have been doing.
80085!!! :d
Euler rode a KH
Natural logs are what you ride on a Mun"e".
please everyone even a simple minded music major can figure out this problem, the answer is as follows:
42