Question 827144
1) cos33pie/4
33π/4=8π+π/4
This is revolving 4 revolutions counter-clockwise around a unit circle plus an additional π/4 which places the reference angle in quadrant I in which cos>0.
cos33pie/4=cos(π/4)=√2/2
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2)tan(21pie)
21π=20π+π
This is revolving 10 revolutions counter-clockwise around a unit circle plus an additional π.
tan(21pie)=tan(π)=0
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3)sec 17pie/4
17π/4=4π+π/4
This is revolving 2 revolutions counter-clockwise around a unit circle plus an additional π/4 which places the reference angle in quadrant I in which sec>0.
sec 17pie/4=sec(π/4)=√2