I have done the segment 1 pratice exam
A)
SLOPE OF f(x)
To find the slope of f(x) we pick two points on the function and use the slope formula. Each point can be written (x, f(x) ) so we are given three points in the table. These are: (-1, -3) , (0,0) and (1,3). We can also refer to the points as (x,y). We call one of the points
and another
. It doesn't matter which two points we use, we will always get the same slope. I suggest we use (0,0) as one of the points since zeros are easy to work with.
Let's pick as follows:
The slope formula is:
We now substitute the values we got from the points to obtain.
The slope of f(x) = 3
SLOPE OF g(x)
The equation of a line is y=mx+b where m is the slope and b is the y intercept. Since g(x) is given in this form, the number in front of the x is the slope and the number by itself is the y-intercept.
That is, since g(x)=7x+2 the slope is 7 and the y-intercept is 2.
The slope of g(x) = 2
B)
Y-INTERCEPT OF g(x)
From the work in part a we know the y-intercept of g(x) is 2.
Y-INTERCEPT OF f(x)
The y-intercept is the y-coordinate of the point where the line crosses the y-axis. This point will always have an x-coordinate of 0 which is why we need only identify the y-coordinate. Since you are given the point (0,0) which has an x-coordinate of 0 this must be the point where the line crosses the y-axis. Since the point also has a y-coordinate of 0, it's y-intercept is 0
So the function g(x) has the greater y-intercept
The expectation value is simply obtained by multiplying the probability of each outcome by each possible value. These are then summed for each outcome to obtain the expectation value. In the board game, if there is a 60% chance that you will move 4 spaces forward (+4) and a 40% chance that you will move back 2 spaces then expected value for number of spaces is (0.6 x 4) + (0.4 x -2) = 2.4 - 0.8 = 1.6 spaces.
Okay, so this is basically telling you that there is no solution. You don't have to worry about there being one. You just have to justify (or explain) why there isn't one.
Basically, neither y or x is equal to anything. You couldn't make x equal to a value in y because x and y are both together in the equation and equal to numbers.
We can always move a factor to the other side. So,
x-2y= -8
Add 2y to the other side.
x= -8+2y
Now, plug in -8+2y as x.
3(-8+2y)- 6y=-12
-24+6y-6y= -12
The 6y's cancel out. So, we can't figure out what y is.
-24=-12 <- no y.
These two lines are parallel. They have direct proportion in each other. That is why there is no solution because the lines never cross. Parallel lines do not cross.
I hope this helps!
~kaikers