SOLUTION: Use the given function value and the trigonometric identities to find the exact value of each indicated trigonometric function 0° ≤ 𝛼 ≤ 90°, 0 ≤ 𝛼 ≤ 𝜋 2

Algebra ->  Trigonometry-basics -> SOLUTION: Use the given function value and the trigonometric identities to find the exact value of each indicated trigonometric function 0° ≤ 𝛼 ≤ 90°, 0 ≤ 𝛼 ≤ 𝜋 2       Log On


   



Question 1203872: Use the given function value and the trigonometric identities to find the exact value of each indicated trigonometric function
0° ≤ 𝛼 ≤ 90°, 0 ≤ 𝛼 ≤
𝜋
2
.
cot(𝛼) = 3
(a)
tan(𝛼)

(b)
csc(𝛼)

(c)
sec(𝛼)

(d)
sin(𝛼)

Found 2 solutions by Theo, MathLover1:
Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
you are given that cot(theta) = 3
cot(theta) = adjacent side divided by opposite side.

if adjacent side is 3, then opposite side is 1.
use pythagorus to solve for hypotenuse.
pythagorus says that hypotenuse squared = adjacent side squared plus opposite side square.
you get hypotenuse squared = 3^2 + 1^2 = 9 + 1 = 10
this makes hypotenuse = sqrt(10)
you have:
adjacent side = 3
opposite side = 1
hypotenuse = 10

(a)
tan(𝛼) = opposite side / adjacent side = 1/3

(b)
csc(𝛼) = hypotenuse / opposite side = sqrt(10)/1 = sqrt(10)

(c)
sec(𝛼) = hypotenuse / adjacent side = sqrt(10)/3

(d)
sin(𝛼) = opposite side / hypotenuse = 1/sqrt(10)

here's a diagram with all the basic trig functions identified.






Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!
+cot%28alpha%29+=+3
Use the definition of cotangent to find the known sides of the unit circle

+cot%28alpha%29+=+adj%2Fopp+
so,
+adj%2Fopp=3
which is same as
+adj%2Fopp=3%2F1
so, +adj=3 and++opp=1

then hypothenuse is:
++hyp=sqrt%28adj%5E2%2Bopp%5E2%29
++hyp=sqrt%283%5E2%2B1%5E2%29
++hyp=sqrt%2810%29


(a)
++tan%28alpha%29=opp%2Fadj

++tan%28alpha%29=1%2F3

(b)
+csc%28alpha%29=hyp%2Fopp+

+csc%28alpha%29=sqrt%2810%29%2F1

++csc%28alpha%29=sqrt%2810%29


(c)


+sec%28alpha%29=hyp%2Fadj

++sec%28alpha%29=sqrt%2810%29%2F3


(d)

+sin%28alpha%29=opp%2Fhyp+

+sin%28alpha%29=1%2Fsqrt%2810%29

+sin%28alpha%29=sqrt%2810%29%2F10