# Evaluating Sine & Cosine and and Tangent (Section 7.4)

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Evaluating Sine & Cosine and and Tangent (Section 7.4)

To express in terms of a reference angle: 2 of 10 1)Find the reference angle of θ 2)Determine the sign ± (quadrant of θ) 3) Write as ± sin In quadrant II sin is + In quadrant III sin is - AS T C

3 of 10 Express each of the following in terms of a reference angle:

Express each in terms of the reference angle: d. cos 660 0 e. cos 115 0 f. sin 334.8 0 4 of 10

5 of 10 To find the value of sin, cos, or tan of angles that are not multiples of 30,45, or 60: Use calculator: Set to “degree” or “radian” mode Round to 4 decimal places

6 of 10 Find the exact value of each of the following: (in fraction form, no calculator) 1)Locate angle (quadrant) 2)Determine reference angle 3)Determine trig value 4)Determine sign (look at quadrant)

Homework: pg. 279 1 – 4 (a & c) 5 – 10 (c) 11 – 18 (a & c)