Question

Question 13

Answer 1

Answer:

71.6 degrees

Step-by-step explanation:

Given the vectors

u= <8,4> v = <9.-9> (5 points)

u*v = (8, 4)*(9, -9)

u*v = 8(9)+(4)(-9)

u*v = 72 - 36

u*v = 36

|u| = √8²+4²

|u| = √64+16

|u| = √80

|v| = √9²+9²

|v|  = √81+81

|v|  = √162

Using the formula

u*v = ||u||v| cos theta

36 = √80(√162)cos theta

36 = √12960 cos theta

cos theta = 36/√12960

cos theta = 36/113.8

cos theta = 0.3162

theta = arccos(0.3162)

theta = 71.56 degrees

Hence the angle between the given vectors to the nearest tenth of a

degree is 71.6 degrees