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SOHCAHTOA. HYP. OPP. X O. SIN X O = OPP……. Trigonometry 1 Learning All The Ratios. Opp’. C. x o. Adj’. A. B. Sine,Cosine & Tangent Ratio. So far you have seen the tangent ratio in action , calculating angles:. Key Result. hyp’.
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SOHCAHTOA HYP OPP XO SIN X O =OPP…… Trigonometry 1Learning All The Ratios.
Opp’ C xo Adj’ A B Sine,Cosine & Tangent Ratio. So far you have seen the tangent ratio in action , calculating angles: Key Result. hyp’ Now we need to look at the two ratios involving the hypotenuse: Opp’ sin xo = hyp’ adj’ It should be noted that in full: sin =sine and cos = cosine cos xo = hyp’
a o 21cm 15cm Using The New Ratios. Calculate the angle a o below. hyp (1) Identify the two sides marked. (2) Choose the correct trig ratio . opp (3) Substitute in values . (4) Calculate the ratio to 3d.p . (5) Use the inverse sine function on your calculator to calculate the angle . a o = 45.6 o
14.8cm b o 9.7cm Calculate the angle b o below. hyp (1) Identify the two sides marked. (2) Choose the correct trig ratio . adj (3) Substitute in values . (4) Calculate the ratio to 3d.p . (5) Use the inverse sine function on your calculator to calculate the angle . b o = 49.1o
Remembering The Ratios. Look again at the three trig ratios given below: Take the first letter of each word. Write the letters in order. S O H C A H T O A To remember all your trig’ ratios just remember the word above.
(2) (1) 29m ao 7.2m 21m bo 3.6m (3) co (4) 6.8cm 2.8cm 9.5cm do 4.9cm What Goes In The Box ? Calculate the unknown angles below deciding each time which trig’ ratio to use. cos sin 60o 46.4o tan cos 35.8o 72.9o