Pearson Algebra 2 Common Core, 2011
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Pearson Algebra 2 Common Core, 2011 View details
3. Right Triangles and Trigonometric Ratios
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Exercise 13 Page 924

Practice makes perfect
a We are given right triangle ABC, and we want to find the value of sin A.

To obtain this, we will use the trigonometric ratio for sine. sin θ = Opposite/Hypotenuse In our case, the length of the opposite leg is 15, the length of the hypotenuse is 17, and the angle is A. sin θ = Opposite/Hypotenuse ⇒ sin A = 15/17 Now, we will find the value as a decimal.

sin A = 15/17
sin A = 0.882352 ...
sin A ≈ 0.88

b Now, we want to find the value of sec A. To do so we will use the trigonometric ratio for secant.

sec θ = Hypotenuse/Adjacent In this case, the length of the adjacent leg is 8, the length of the hypotenuse is 17, and the angle is A.

Next, we can rewrite the trigonometric ratio for secant by substituting these values. sec θ = Hypotenuse/Adjacent ⇒ sec A = 17/8 Let's find the value as a decimal!

sec A = 17/8
sec A = 2.125
sec A≈ 2.13

c The next value is cot A. We can find its value by recalling the trigonometric ratio for cotangent.

cot θ = Adjacent/Opposite We know that the length of the adjacent leg is 8, the length of the opposite leg is 15 and the angle is A.

We can rewrite the trigonometric ratio for cotangent by using these values. cot θ = Adjacent/Opposite ⇒ cot A = 8/15 The next step will be calculating the value as a decimal.

cot A = 8/15
cot A = 0.533333 ...
cot A ≈ 0.53

d We want to find the value of csc B. To do that, we will to use the trigonometric ratio for cosecant.

csc θ = Hypotenuse/Opposite In this case, the length of the opposite leg is 8, the length of the hypotenuse is 17, and the angle is B.

The next step will be rewriting the trigonometric ratio for cosecant by substituting these values. csc θ = Hypotenuse/Opposite ⇒ csc B = 17/8 As the last step, we will find the value as a decimal.

csc B = 17/8
csc B = 2.125
csc B ≈ 2.13

e We can find the value of sec B by recalling the trigonometric ratio for secant.

sec θ = Hypotenuse/Adjacent This time the length of the hypotenuse is 17, the length of the adjacent leg is 15, and the angle is B.

Next, we can rewrite the trigonometric ratio for secant by substituting these values. sec θ = Hypotenuse/Adjacent ⇒ sec B = 17/15 We will calculate this value as a decimal. Let's do it!

sec B = 17/15
sec B = 1.133333 ...
sec B ≈ 1.13

f The last value is tan B. To obtain it, we will use the trigonometric ratio for tangent.

tan θ = Opposite/Adjacent For this case, the length of the opposite leg is 8, the length of the adjacent leg is 15, and the angle is B.

Now, we can rewrite the trigonometric ratio for tangent by substituting these values. tan θ = Opposite/Adjacent ⇒ tan B = 8/15 Finally, we will find the value as a decimal.

tan B = 8/15
tan B = 0.533333 ...
tan B ≈ 0.53