Find the exact value of the remaining trig functions: sec theta=-5/4, tan theta<0
\[\cos(\theta) = -4/5\]
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using that, we can get all the other ratio values
\[\sin(\theta)=3/5\]\[\cos(\theta)=-4/5\]\[\tan(\theta)=-3/4\]\[\csc(\theta)=5/3\]\[\sec(\theta)=-5/4\]\[\cot(\theta) = -4/3\]
How do I find all of them?
Use the trig identity: sec^2 x = 1 + tan ^2 x . Find the arc x knowing sec x = -5/4. 25/16 = 1 + tan^2x --> tan^2 x = 25/16 - 16/16 = 9/16 tan x = -3/4 and tan x = 3/4. Calculators will give 2 values of x. The answer that gives sec = -5/4 will be selected.
o = opposite a = adjacent h = hypotenuse sin(θ) = o/h cos(θ) = a/h tan(θ) = o/a csc(θ) = h/o sec(θ) = h/a cot(θ) = a/o
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do you know SOHCAHTOA?
That's basically all I know.
take a look at this then: http://www.math.uci.edu/sites/math.uci.edu/files/trig.pdf
Just the left portion of the first page
nvm, just look at this instead
going back to your original question, sec(θ) = 1/cos(θ) so, cos(θ) = -4/5
cos theta=1/sec theta=-1/5/4=-4/5 For sin theta use: sin^2 theta+cos^2 theta=1 Put the value for cos theta and get sin theta. After you get sin theta use 1/sin theta to get cosec theta. After you get the values of sin theta and cos theta, you can get the value of tan theta by using: tan theta= sin theta/cos theta. Good luck
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