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Mathematics 15 Online
OpenStudy (poofypenguin):

Trig help. Attachment to follow.

OpenStudy (poofypenguin):

OpenStudy (poofypenguin):

My attempt at trying to simplify the first one doesn't seem to be going anywhere...i'm working on attaching a pic, just a sec.

OpenStudy (poofypenguin):

OpenStudy (anonymous):

sin square x plus cos square x is equal to 1

OpenStudy (poofypenguin):

alrigh, but can i do anything with the rest of it?

OpenStudy (anonymous):

\[\sin ^{2}x + \cos ^{2}x = 1\]

OpenStudy (anonymous):

Use the identity : \[\sin^2x + \cos^2x = 1\]

OpenStudy (campbell_st):

ok... looking at choice D this is the expansion, you just need to finish it \[\frac{ 1 - (\cos(x))^2}{(\cos(x)} = \frac{1 - 1 + \sin^2(x)}{\cos(x)} = \frac{\sin^2(x)}{\cos(x)} = \sin(x) \times \frac{\sin(x)}{\cos(x)}\]

OpenStudy (anonymous):

@PoofyPenguin , the answer is A-5 B-3 C-2 D-4 E-1

OpenStudy (poofypenguin):

Could you please explain?

OpenStudy (anonymous):

sure which part

OpenStudy (campbell_st):

don't forget that for A \[\tan(x) = \frac{\sin(x)}{\cos(x)} = \sin(x) \times \frac{1}{\cos(x)}\] whats 1/cos(x)

OpenStudy (poofypenguin):

Alright, but the my solution that i posted initally, what do i do after the sin^2x+cos^2x=1 identity?

OpenStudy (ajprincess):

For the one u tried use the identity \(\cos^2x+\sin^2x=1\) as both @fall2012 and @waterineyes said. then factorise the numerator. Try to cancel common factors in both numerator and denominator if there are any.

OpenStudy (anonymous):

Solving 1 part: \[\frac{\cos^2x + 1 + \sin^2x - 2\sin^2x}{(1 - sinx)cosx} \implies \frac{2(1 - sinx)}{(1 - sinx)cosx} \implies 2\sec(x)\]

OpenStudy (anonymous):

So E part gets combined with 1..

OpenStudy (campbell_st):

look at answer 3 take out the common factor \[\sec(x)(1 - \sin^2(x)) = \sec(x)(\cos^2(x)) = \frac{1}{\cos(x)} \times \cos^2(x)\]

OpenStudy (anonymous):

Part A is tan(x) Also sin(x)sec(x)=sin(x)/cos(x)=tan(x) hence A=5

OpenStudy (campbell_st):

thats enough from me... and hope it all helps..

OpenStudy (poofypenguin):

Yes, it helped very much! Thank you! :D

OpenStudy (anonymous):

Solving part 2 : \[\frac{\sin(x)}{\cos(x)} + \frac{\cos(x)}{\sin(x)} \implies \frac{\sin^2(x) + \cos^2(x)}{\sin(x) \cos(x)} \implies \frac{1}{\sin(x) \cos(x)} = Solve\]

OpenStudy (anonymous):

And it is attaching to part C. So : C is attaching to 2..

OpenStudy (anonymous):

What else remains @PoofyPenguin

OpenStudy (poofypenguin):

I'm still having issues with the one i initially posted... i can't seem to figure out how it was simplified

OpenStudy (anonymous):

I have solved the same above in my second post...

OpenStudy (ajprincess):

Also remember \[\frac{ 1 }{ sinx }=cscx\] \[\frac{ 1 }{ cosx }=secx\]

OpenStudy (poofypenguin):

I can't seem to figure out how you got to \[2\sin ^{2}x\]

OpenStudy (anonymous):

\[\frac{\cos(x)}{1 - \sin(x)} + \frac{1 - \sin(x)}{\cos(x)} \implies \frac{\cos^2(x) + (1 - \sin(x))^2}{(1- \sin(x)) \cos(x)}\] I have got this by taking LCM.. Getting ??

OpenStudy (anonymous):

Oh sorry that is 2sinx not 2sin^2(x)

OpenStudy (anonymous):

\[\frac{\cos^2(x) + \sin^2(x) + 1 - 2\sin(x)}{(1-\sin(x))\cos(x)} \implies \frac{2 - 2\sin(x)}{(1 - \sin(x))\cos(x)}\]

OpenStudy (poofypenguin):

Yep! That's what i got so far, so i guess i would factor out the 2 next?

OpenStudy (ajprincess):

ya

OpenStudy (anonymous):

Yep go for it...

OpenStudy (poofypenguin):

Yay! I got it! Thanks again!

OpenStudy (anonymous):

Welcome.. I said you no that ajprincess is here so don't worry.. Where I will be wrong she will there to correct me.. Ha ha ha.. Feeling very safe..

OpenStudy (poofypenguin):

Ha ha ha!

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