If the point (-2,3) lies on the terminal side of an angle alpha, find the value of cos alpha

Can (2,3 and square root 10) be sides ona right triangle?

3-12. write each answer with a reasonable number of figures. find the absolute uncertainty and percent relative uncertainty for each answer. (a) [12.41 (±0.09) + 4.16 (±0.01)] x 7.068 2 (±0.000 4) =? (b) [3.26 (±0.10) x 8.47 (±0.05)] - 0.18 (±0.06) =? (c) 6.843 (±0.008) x 104 + [2.09 (±0.04)- 1.63 (±0.01)] =?

20 da is equal to a. 2,000 cm. b. 2 m. c. 20,000 cm. d. 20,000 mm