Chapter 10 - Radical Expressions and Equations - 10-6 Trigonometric Ratios - Got It? - Page 646: 2

Answers to a, c, and d are rounded the nearest ten-thousandth. a)$ 0.9848$ b) $1$ c) $0.9659$ d) $0.1564$ e) They are equal. The reason for this is that when an angle in a right-triangle is $45^{o}$, the adjacent side and the opposite side are equal. Since sine is the measure of the opposite side divided by the measure of the hypotenuse and cosine is the measure of the adjacent side divided by the measure of the hypotenuse, sine and cosine for the angle 45 degrees is equal.

For question a, b, c, and d, type the expression into the calculator to get the value, and make sure you are in degrees mode. e) They are equal. The reason for this is that when an angle in a right-triangle is $45^{o}$, the adjacent side and the opposite side are equal. Since sine is the measure of the opposite side divided by the measure of the hypotenuse and cosine is the measure of the adjacent side divided by the measure of the hypotenuse, sine and cosine for the angle 45 degrees is equal.