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a. Drill 3/15/12. c. Name a ratio equal to if the triangles are similar: . f. e. c. b. a. d. Objective. STW learn the vocabulary relating angles to sides in right triangles for trigonometry STW explore the sine and cosine ratios, and two of the properties associated with them.
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a Drill 3/15/12 c • Name a ratio equal to if the triangles are similar: f e c b a d
Objective • STW learn the vocabulary relating angles to sides in right triangles for trigonometry • STW explore the sine and cosine ratios, and two of the properties associated with them.
Objective • SW explore the sine and cosine ratios, and two of the properties associated with them.
Greek Letters • angle theta
Side Names in relation to • hypotenuse
Side Names in relation to • Adjacent side (means next to)
Side Names in relation to • Opposite side (means across from)
Abbreviations: hypotenuse (hyp.) opposite (opp.) Adjacent (adj.)
Tangent Ratios: • Tangent ratio of = opp./adj. opp. (alpha) adj.
Abbreviation: • Tan = opp./adj. opp. adj.
Abbreviation: • Find Tan = 3 5
Abbreviation: • Find Tan A= 7 A 2
Abbreviation: B • Find Tan B= 7 2
Abbreviation: • Find Tan = 5 3
Abbreviation: • Find Tan = b a
Calculator: • Find Tan =, if =35
Calculator: • Change to degree mode • Hit tan 35
Calculator: • Hit tan 35 • Tan 35 ≈ 0.7
Inverse Tangent: • If Tan =opp/adj, then the inverse tangent, abbreviated tan-1(also referred to as arctan)is used to find the angle, when given the sides
Abbreviation: • Find : • tan =5/3 • tan-1 (tan )= • =tan-1(5/3)=? 3 tan-1(5/3) 5
Use a calculator: • =tan-1(5/3)=? • Hit 2nd tan (5/3) • =59.04 You must use degree mode!!
Sine Ratios: • Sine ratio of = opp./hyp. hyp. opp.
Abbreviation: • Sin = opp./hyp. hyp. opp.
Finding Sine Ratios: • sin = ? 7 5
Cosine Ratios: • Cosine ratio of = adj./hyp. hyp. adj.
Abbreviation: • Cos = adj./hyp. hyp. adj.
Finding Cosine Ratios: • cos = ? 7 5
Calculator: • Find sin and cos , if =35
Calculator: • Change to degree mode • Hit sin 35
Calculator: • Hit sin 35 • sin 35 ≈ 0.57
Calculator: • Change to degree mode • Hit cos 35
Calculator: • Hit cos 35 • cos 35 ≈ 0.82
Inverse sine and cosine: • If sin =opp/hyp and cos =adj/hyp, then the inverse sin and cos, abbreviated sin-1 and cos-1(also referred to as arcsin and arccos)is used to find the angle, when given the sides
CW/HW • Example Ex 11-1 # 1-12 and • Example Ex All