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Unformatted text preview: Trigonometric Functions of Any Angle Section 1.4 27 Example 1.20 x y 120 radicallow 3 1 2 ( 1, radicallow 3) 60 Find the exact values of all six trigonometric functions of 120 . Solution: We know 120 = 180 60 . By Example 1.7 in Section 1.2, we see that we can use the point ( 1, radicallow 3) on the terminal side of the angle 120 in QII, since we saw in that example that a basic right triangle with a 60 angle has adjacent side of length 1, opposite side of length radicallow 3, and hypotenuse of length 2, as in the figure on the right. Drawing that triangle in QII so that the hypotenuse is on the terminal side of 120 makes r = 2, x = 1, and y = radicallow 3. Hence: sin 120 = y r = radicallow 3 2 cos 120 = x r = 1 2 tan 120 = y x = radicallow 3 1 = radicallow 3 csc 120 = r y = 2 radicallow 3 sec 120 = r x = 2 1 = 2 cot 120 = x y = 1 radicallow 3 Example 1.21 x y 225 1 1 2 ( 1,...
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This note was uploaded on 01/21/2012 for the course MAC 1130 taught by Professor Dr.cheun during the Fall '11 term at FSU.
 Fall '11
 Dr.Cheun
 Calculus

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