QR Trig problem

[tisler]

tanx=15/17, what is (cosx + 17sinx)/(cosx-17sinx)?

I have no idea...
can anybody show me how to set it up??

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[drzakisadiq]

tanx=15/17, what is (cosx + 17sinx)/(cosx-17sinx)?

I have no idea...
can anybody show me how to set it up??

Remember this mneumonic device for trig functions

SOHCAHTOA
sin x = opp/hyp
cos x = adj/hyp
tan x = opp/adj

so if tan x = 15/17
if you do pythagorean theorem, you can figure out the hyp and go from there

 

[Streetwolf]

tanx=15/17, what is (cosx + 17sinx)/(cosx-17sinx)?

I have no idea...
can anybody show me how to set it up??

tan x = sin x / cos x

Thus sin(x)/cos(x) = 15/17 which means 17sin(x) = 15cos(x).

I see a couple 17s in that problem.

 

[nzaads]

what's the answer?

 

[winkipink]

is it -8/7?

tanx = 15/17
sinx/cosx = 15/17
manipulate this:
17sinx= cosx15

cosx +17sinx
------------
cos x -17sinx

plug n chug (i used cosine as the variable):

cosx + 15cosX
--------------
cos x - 15 cosx

= 16cosx
--------
-14 cosx

cosx's cancel out

= 16/-14 = -8/7

 

[tisler]

is it -8/7?

tanx = 15/17
sinx/cosx = 15/17
manipulate this:
17sinx= cosx15

cosx +17sinx
------------
cos x -17sinx

plug n chug (i used cosine as the variable):

cosx + 15cosX
--------------
cos x - 15 cosx

= 16cosx
--------
-14 cosx

cosx's cancel out

= 16/-14 = -8/7

You are indeed right and I feel stupid because this question was a lot easier than it looked.
Thank you all for answering my question.

 

[winkipink]

don't feel stupid i thought it was hard too.