Problema 13
Use the given triangles to evaluate each expression. If necessary, express the value without a square root in the denominator by rationalizing the denominator.
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tan 𝜋/3
Problema 15
In Exercises 9–16, use the given triangles to evaluate each expression. If necessary, express the value without a square root in the denominator by rationalizing the denominator.

sin 𝜋/4 - cos 𝜋/4
Problema 16
In Exercises 9–16, use the given triangles to evaluate each expression. If necessary, express the value without a square root in the denominator by rationalizing the denominator.

tan 𝜋/4 + csc 𝜋/6
Problema 28
In Exercises 25–30, use an identity to find the value of each expression. Do not use a calculator. sin² 𝜋 + cos² 𝜋 10 10
Problema 29
In Exercises 25–30, use an identity to find the value of each expression. Do not use a calculator. sec² 23° - tan² 23°
Problema 31
In Exercises 31–38, find a cofunction with the same value as the given expression. sin 7°
Problema 32
Find a cofunction with the same value as the given expression.
sin 19°
Problema 33
In Exercises 31–38, find a cofunction with the same value as the given expression. csc 25°
Problema 34
Find a cofunction with the same value as the given expression.
csc 35°
Problema 35
In Exercises 31–38, find a cofunction with the same value as the given expression. tan 𝜋 9
Problema 36
Find a cofunction with the same value as the given expression.
tan (𝜋/7)
Problema 37
In Exercises 31–38, find a cofunction with the same value as the given expression. cos 2𝜋 5
Problema 38
Find a cofunction with the same value as the given expression.
cos (3𝜋/8)
Problema 39
In Exercises 39–48, use a calculator to find the value of the trigonometric function to four decimal places.
sin 38°
Problema 41
In Exercises 39–48, use a calculator to find the value of the trigonometric function to four decimal places.
tan 32.7°
Problema 43
In Exercises 39–48, use a calculator to find the value of the trigonometric function to four decimal places.
csc 17°
Problema 45
In Exercises 39–48, use a calculator to find the value of the trigonometric function to four decimal places.
cos 𝜋/10
Problema 47
In Exercises 39–48, use a calculator to find the value of the trigonometric function to four decimal places.
cot 𝜋/12
Problema 49
In Exercises 49–54, find the measure of the side of the right triangle whose length is designated by a lowercase letter. Round answers to the nearest whole number.
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Problema 53
In Exercises 49–54, find the measure of the side of the right triangle whose length is designated by a lowercase letter. Round answers to the nearest whole number.

Problema 1.3.52
In Exercises 35–60, find the reference angle for each angle. 553°
Problema 1.3.61
In Exercises 61–86, use reference angles to find the exact value of each expression. Do not use a calculator. cos 225°
Problema 1.3.60
In Exercises 35–60, find the reference angle for each angle. -13𝜋/3
Problema 1.3.75
In Exercises 61–86, use reference angles to find the exact value of each expression. Do not use a calculator. tan(-𝜋/4)
Problema 1.3.59
Find the reference angle for each angle.
-25π/6
Problema 1.3.64
In Exercises 61–86, use reference angles to find the exact value of each expression. Do not use a calculator. sec 240°
Problema 1.3.55
Find the reference angle for each angle.
23π/4
Problema 1.3.49
Find the reference angle for each angle.
4.7
Problema 1.3.69
In Exercises 61–86, use reference angles to find the exact value of each expression. Do not use a calculator. csc(7𝜋/6)
Problema 1.3.57
In Exercises 35–60, find the reference angle for each angle. - 11𝜋 / 4
Ch. 1 - Angles and the Trigonometric Functions
