Answer:
<em>71.6 degrees </em>
Step-by-step explanation:
The formula for calculating the angle between two vectors is expressed as;
u.v = |u||v|cos theta
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+(-9)²
|v| = √81+81
|v| = √162
36 = √80*√162 cos theta
36 = √12960 cos theta
36 = 113.84 cos theta
cos theta = 36/113.84
cos theta = 36/113.84
cos theta = 0.3162
theta = arccos (0.3162)
<em>theta = 71.6 degrees </em>
<em>Hence the angle between the given vectors is 71.6 degrees </em>
2 71
3 86
4 101
6 131
.................
There are two ways to approach this.
Option #1:
Use the slope formula 
.
That value is undefined, so the slope is undefined.
Option #2:
Because the two points have the same x-value, they will be vertically above/below one another. This means your line is a vertical line and the slope of a vertical line is undefined.
Either way, your slope is undefined.
The answer is C
1,500,000,000
An equation is a math problem that must be solved to find out to find out a difference, quotient, sum, or product.
An inequality is a math problem that must be solved to find out what the difference is between two numbers.
