tanx=-4.25

Trigonometric ratios and functions, the unit circle, inverse trig functions, identities, trig graphs, etc.
sully039
Posts: 16
Joined: Mon Jul 25, 2011 8:33 pm
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tanx=-4.25

I can't figure out this problem: Determine all possible values of x to one decimal place, for -pi<x<3pi
tanx=-4.25
To start off, how would I get the reference angle?
Oh and the answer is supposed to be -1.3, 4.9, 8.1

Thanks

little_dragon
Posts: 220
Joined: Mon Dec 08, 2008 5:18 pm
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Re: tanx=-4.25

sully039 wrote:I can't figure out this problem: Determine all possible values of x to one decimal place, for -pi<x<3pi
tanx=-4.25
To start off, how would I get the reference angle?

i dont think U can do ref angles 4 this
R U allowed to use inv-tan on your calc?

sully039
Posts: 16
Joined: Mon Jul 25, 2011 8:33 pm
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Re: tanx=-4.25

The thing is I tried getting the inv of tan but my tutor said that that wasnt't the way to get the reference angle...

nona.m.nona
Posts: 283
Joined: Sun Dec 14, 2008 11:07 pm
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Re: tanx=-4.25

The point, I believe, is that "-4.25" does not correspond to any of the reference angles, being:

$0,\, \frac{\pi}{6},\, \frac{\pi}{4},\, \frac{\pi}{3},\, \frac{\pi}{2}\, \pi$

The tangent values for the above angles do not correspond to the given tangent value. There is nothing to "work back to". If you aren't supposed to be using your calculator, are you perhaps supposed to be using tables of trig values?

sully039
Posts: 16
Joined: Mon Jul 25, 2011 8:33 pm
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Re: tanx=-4.25

Hey guys it turned out I did have to do tan-14.25 but without the negative sign -_-
So the reference angle would be 1.34 and then i was able to find the other values.

Thanks for the help