5-4 Vectors, Dot Product, Angle, and Projection (AP Precalculus)

• 21

• -7

• 2

• -5

Fill in the blank: The dot product of vector u and vector v is -20. What is the missing x-component of v?

u = <-3, -1, 4>

v = < ??, 8, 3>

• -7

• 6

• 8

• -31

• 8

• 12

• 7

• 14

Fill in the blank: Vector a and vector b both point in the same direction.

a = < -6, -2, 8>

b = < _x_ , -12, 48 >

What is the value of _x_?

• -36

• 36

• 18

• -24

Fill in the blank: Vector a and vector b are perpendicular.

a = < -6, -2, 8>

b = < _x_ , -12, 48 >

What is the value of _x_?

• -68

• 68

• 36

• -24

• 6

• -4

• 1

• 17

Find the angle between vectors a and b. Round your answer to the nearest degree. The angle between vectors is given by cos(theta) = (a.b)/(|a||b|).

a = < 3,-7,2 >

b = < 2,2,1 >

• 35

• 75

• 105

• 135

Find the angle between the vectors. Round your answer to the nearest degree. The angle between vectors is given by cos(theta) = (a.b)/(|a||b|).

v = < -9, 6 >

w = < -1, -2 >

• 28

• 111

• 63

• 97

Calculate the angle in degrees between u=<3, 4> and v=<-4, 3>.

• 90

• 37

• 53

• 135

Calculate the angle in degrees between u=<3, 4> and v=<-6, -8>.

• 90

• 106

• 180

• 74