MA 154 Lesson 3 DelworthMA 154 Lesson 3 DelworthSection 6.2 Trigonometric Functions of AnglesThe Fundamental Identities:(1) The reciprocal identities:csc1sinsec1coscot1tan(2) The tangent and cotangent identities:tansincoscotcossin(3) The Pythagorean identities:sin2 cos21 1 tan2sec21 cot2csc2Take the simple right triangle with sides 3, 4 and 5 with opposite the side of length 4.Find sin and cos, now find sin2 cos2sin2 cos21 is a Pythagorean identity since it is derived from the Pythagorean Theorem.Divide both sides by sin2to find another Pythagorean identity.Divide both sides by cos2to find yet another one.Each of the three Pythagorean identities creates two more identities by subtracting a term from the left side to the right side. sin2 cos21 1 tan2sec21 cot2csc2sin21 cos2tan2sec2 1 cot2csc2 1cos21 sin21sec2 tan21csc2 cot2Verify the identity by transforming the left side into the right side.tancot1sin 3 cot 3 cos 3 1MA 154 Lesson 3 DelworthSection 6.2 Trigonometric Functions of Anglessectancscsin2 cos2sin21 cot2(1 cos)(1 cos) sin2cos2sec2 1 sin21 sin2 1 tan2 1cot tancscsec 2MA 154 Lesson 3 DelworthSection 6.2 Trigonometric Functions of AnglesUsing the coordinate system, Notice that the adjacent side corresponds to the x-value of the coordinate and the opposite side corresponds the y-value of the coordinateThe idea that the cosine of corresponds to the x-axis and the sine of corresponds to the y-axis is one that you need to get use to.If is an angle in standard position on a rectangular coordinate system and if P(-5, 12) is on theterminal side of , find the values of the six trigonometric functions of .If is an angle in standard position on a rectangular coordinate system and if P(4, 3) is on the terminal side of , find the values of the six trigonometric functions of .Find the exact values of the six trigonometric functions of if is in standard position and the terminal side of is in the specified quadrant and satisfies the given condition.III; on the line 4x – 3y = 0 II; parallel to the line 3x + y – 7 = 03(x, y)MA 154 Lesson 3 DelworthSection 6.2 Trigonometric Functions of AnglesFind the quadrant containing if the given conditions are true.a) tan < 0 and cos > 0b) sec > 0 and tan < 0c) csc > 0 and cot < 0d) cos < 0 and csc < 0Use the fundamental identities to find the values of the trigonometric functions for the given conditions:tan125 and cos 0sec 4 and csc 0
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