Trig Ratios C 5 2 A M 4. If C = 20º, then cos C is equal to: Be sure to discuss if C = 20, then sin C would equal ? 4. If C = 20º, then cos C is equal to: A. sin 70 B. cos 70 C. tan 70
hypotenuse hypotenuse opposite opposite adjacent adjacent
Finding an angle. (Figuring out which ratio to use and getting to use an inverse trig button.)
Ex: 1. Figure out which ratio to use. Find x Ex: 1 Figure out which ratio to use. Find x. Round to the nearest tenth. 20 m 40 m Shrink yourself down and stand where the angle is. Tan-1 20 / 40 ) Now, figure out which trig ratio you have and set up the problem.
Ex: 1. Figure out which ratio to use. Find x Ex: 1 Figure out which ratio to use. Find x. Round to the nearest tenth. 15 m 50 m Shrink yourself down and stand where the angle is. Sin-1 15 / 50 ) Now, figure out which trig ratio you have and set up the problem.
Ex. 3: Find . Round to the nearest degree. 17.2 9
Ex. 4: Find . Round to the nearest degree. 7 23
Ex. 5: Find . Round to the nearest degree. 200 400
Finding a side. (Figuring out which ratio to use and getting to use a trig button.)
When we are trying to find a side we use sin, cos, or tan. When we are trying to find an angle we use (INVERSE) sin-1, cos-1, or tan-1.