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4.3 Right Triangle Trigonometry. Objectives: Evaluate trigonometric functions of acute angles Use the fundamental trigonometric identities Use trigonometric functions to model and solve real-life problems. Trigonometric Functions. Given a right triangle with acute angle . hyp. opp. .
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4.3 Right Triangle Trigonometry Objectives: Evaluate trigonometric functions of acute angles Use the fundamental trigonometric identities Use trigonometric functions to model and solve real-life problems
Trigonometric Functions Given a right triangle with acute angle hyp opp adj 4.3 Right Triangle Trigonometry
Evaluate the six trig functions of the angle shown in the right triangle sin = cos = tan = csc = sec = cot = 5 13 12 Example 1 4.3 Right Triangle Trigonometry
30° 15 x Example 2 • Find the value of x for the right triangle shown 4.3 Right Triangle Trigonometry
B 62° c 6 A C b Example 3 • Solve ∆ABC 4.3 Right Triangle Trigonometry
B c a 30° A C You Try • Solve ∆ABC 4.3 Right Triangle Trigonometry
Special Triangles30º-60°-90° Recall the conversions 30°= 60°= 60° 2 1 30° 4.3 Right Triangle Trigonometry
Special Triangles45º-45°-90° • Recall the conversion • 45°= 45° 1 45° 1 4.3 Right Triangle Trigonometry
Co-functions of Complementary Angles • Look back at the sines and cosines for the 30-60-90 triangle • Note that sin 30°=cos 60° • Co-functions of complementary angles are equivalent 4.3 Right Triangle Trigonometry
Trigonometric Identities • Reciprocal Identities 4.3 Right Triangle Trigonometry
Trigonometric Identities • Quotient Identities 4.3 Right Triangle Trigonometry
Trigonometric Identities • Pythagorean Identities Note: sin2 is (sin )2 not sin (2) 4.3 Right Triangle Trigonometry
Example 4 • Given sin=0.6, find the value of cos • Given sin=0.6, find the value of tan 4.3 Right Triangle Trigonometry
Example 5 Use trigonometric identities to transform one side of the equation into the other. • cossec=1 • (sec+tan)(sec-tan)=1 4.3 Right Triangle Trigonometry
Surveying • A surveyor is standing 50 ft from the base of a large tree. The surveyor measures the angle of elevation to the top of the tree as 71.5°. How tall is the tree? 4.3 Right Triangle Trigonometry
River Walk • You are 200 yards from a river. Rather than walking directly to the river, you walk 400 yards along a straight path to the river’s edge. Find the acute angle ө between this path and the river’s edge. 4.3 Right Triangle Trigonometry
Skateboarding • Find the length c of the skateboard ramp. 4.3 Right Triangle Trigonometry
Homework • Star Wars Worksheet • Page 285 44-54 even, 79-82 all 4.3 Right Triangle Trigonometry