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# trigonometric function

A point on the terminal side Θ is (2/5, 5/8) determine the exact value of the 6 trigonometric fictional of Θ

### 2 Answers by Expert Tutors

Alex V. | College doesn't make you smart. College teaches you to be resourceful.College doesn't make you smart. College ...
4.8 4.8 (73 lesson ratings) (73)
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given (a,b) = (2/5,5/8)

c = SQRT[(2/5)2+ (5/8)2]

Sin = (5/8)/SQRT[4/25+25/64]

Cos = (2/5)/SQRT[4/25+25/64]

Tan = (5/8)/(2/5)= 25/16

Csc = 1/Sin = SQRT[4/25+25/64]/(5/8)

Sec = 1/Cos = SQRT[4/25+25/64]/(2/5)

Cot = 1/Tan = 16/25
Andre W. | Friendly tutor for ALL math and physics coursesFriendly tutor for ALL math and physics ...
5.0 5.0 (3 lesson ratings) (3)
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You have a right triangle whose adjacent side relative to θ is 2/5 and whose opposite side is 5/8. According to the Pythagorean theorem, the hypotenuse is
√( (2/5)²+(5/8)² ) = √(881) /40.

Now use SOH-CAH-TOA:
sin(θ) = (5/8)/(√(881) /40) = 25 /√(881) (rationalize the denominator if you like)
cos(θ) =(2/5)/(√(881) /40) = 16 /√(881)
tan(θ) = (5/8)/(2/5) = 25/16

The other three trig functions are the reciprocals of these:
sec(θ) = 1/cos(θ) = √(881) /16
csc(θ) = 1/sin(θ) = √(881) /25
cot(θ) = 1/tan(θ) = 16/25