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unit 9 lesson 5.notebook May 21, 2015 Warm Up (Exam Review) Unit 9 Lesson 4 HW Answers Using y = x2 + 2x + 3, 1. 120.7 ft a. find the zeros 2. 65.40 b. find the yintercept 3. 10.5 ft c. determine the domain & range 4. 1427.2 ft d. find the axis of symmetry 5. a: tan A = d/120 e. find the vertex b. 51.30 f. graph c. 590 6. 7. May 2010:47 AM Law of Sines If ABC is a triangle with sides a, b, and c, then May 2010:49 AM For the triangle in the figure, A=30˚, B=45˚, and a= 32. Find the remaining angles and sides C C 32 a b 300 . A A c May 202:22 PM 450 B B May 202:27 PM Ex 2) C = 102.30, B = 28.70, and b = 27.4 feet. Find the remaining angles and sides. Because of prevailing winds, a tree grew so that it was leaning 6˚ from the vertical. At a point 30 meters from the tree, the angle of elevation to the top of the tree is 22˚. Find the height h of the tree. May 202:29 PM May 202:30 PM 1 unit 9 lesson 5.notebook May 21, 2015 Practice Ex 4) A pole tilts toward the sun at a 980 angle from the vertical, and it casts a 22foot shadow. The angle of elevation from the tip of the shadow to the top of the pole is 430. How tall is the pole? 3. A = 360, a = 8, b = 5 16.70, a = 21.6 4. A = 102.40, C = 5. A = 830, C = 54.60, c = 18.1 16 6. A = 1100, a = 48, b = 7. Because of prevailing winds, a tree grew so that it was leaning 40 from the vertical. At a point 35 meters from the tree, the angle of elevation to the top of the tree is 230. Find the height (h) of the tree. 8. A flagpole at a right angle to the horizontal is located on a slope that makes an angle of elevation of 120 with the horizontal. The flagpole’s shadow is 16 meters long and points directly up the slope. The angle of elevation from the tip of the shadow to the sun is 200. Find the height of the flagpole. May 202:31 PM May 202:32 PM Find the remaining angles and side of triangle ABC. If you are given three sides (SSS), or two sides and their included angle (SAS), none of the ratios in the Law of Sines would be complete. In such cases, you can use the Law of Cosines. 16 800 12 May 202:33 PM Example 2: Solve the triangle if A = 950, b = 12 and c = 15. May 202:34 PM Practice 1. 2. A = 1350, b = 4, c = 9 15 300 30 3. To approximate the length <javascript:de ('/Glossary/glossaryterm.aspx?word=Length',%20500, 20500);> of a lake, a surveyor starts at one end of the lake and walks 245 yards. He then turns 110º and walks 270 yards until he arrives at the other end of the lake. Approximately how long is the lake? May 202:35 PM 4. You are heading to Beech Mountain for a ski trip. Unfortunately, state road 105 in North Carolina is blocked off due to a chemical spill. You have to get to Tynecastle Highway which leads to the resort at which you are staying. NC105 would get you to Tynecastle Hwy in 12.8 miles. The detour begins with a 18 veer off onto a road that runs through the local city. After 6 miles, there is another turn <javascript:de ('/Glossary/glossaryterm.aspx?word=Turn',%20500,%20500);> that leads to Tynecastle Hwy. Assuming that both roads on the detour are straight, how many extra miles are you traveling to reach your destination? May 202:35 PM 2 unit 9 lesson 5.notebook May 21, 2015 May 2110:13 AM 3