Answer:
Angle between the two vectors is 135°
u•v = -12
Step-by-step explanation:
Given two vectors u = (4,0) and v = (-3,-3).
To find the angle between the two vectors we will use the formula for calculating the angle between two vectors as shown;
u•v = |u||v|cos theta
cos theta = u•v/|u||v|
theta = arccos (u•v/|u||v|)
u•v = (4,0)•(-3,-3)
u•v = 4(-3)+0(-3)
u•v = -12
For |u| and |v|
|u| = √4²+0²
|u| = √16 = 4
|v| = √(-3)²+(-3)²
|v| = √9+9
|v| = √18
|v| = 3√2
|u||v| = 4×3√2 = 12√2
theta = arccos(-12/12√2)
theta = arccos(- 1/√2)
theta = -45°
Since cos is negative in the second quadrant, theta = 180-45°
theta = 135°
To get u•v using the formula u•v = |u||v|cos theta
Given |u||v| = 12√2 and theta = 135°
u•v = 12√2cos 135°
u•v = 12√2× -1/√2
u•v = -12√2/√2
u•v = -12
For the diagram of the vectors, find it in the attachment below.
Answer:
8 cents
Step-by-step explanation:
To find out how much money Jada had before seling the balloon, we can subtract 5 from 13.
13 - 5 = 8
So, Jada had 8 cents before selling the balloon.
X + y = 40.....multiply by -4
4x + 6y = 180
-------------------
-4x - 4y = -160 (result of multiplying by -4)
4x + 6y = 180
------------------add
2y = 20
y = 20/2
y = 10 <===
x = 30
Answer:
B, D, and E.
Step-by-step explanation:
A) The system has infinitely many solutions. This is wrong because according to the graph, there is only one solution- where the lines intersect. This would only be true if the lines never intersected.
B) A solution to the system is (-1, -2). This is true because this is the only point where the lines intersect.
C) A solution to the system is (0, -1). Since these aren't parabolas and the one above is true, we can say this is false. Also, the lines don't intersect at (0, -1).
D) One of the equations is y=x-1. This is true because the y-intercept for the red line is -1 and the slope of the equation is 1. You can also find this out by directly solving for the equation.
E) One of the equations is 3x+y=-5. If you put this into slope-intercept form, you will find out that the equation is y=-3x-5. This is true because the y-intercept of this is -5 and the slope of this is -3.
