Use the graph of f below to find f(0).?

Question

Picture (or draw) a four quadrant graph with a sloped line running between the points (-10,0) (10,4).

Using this..graph of "f" find f(0). I don't have a clue and can't find a formula to even attempt to figure this one out.

Answer 1

If you are supposed to do it by graph, then it's easy. Just place the points on the graph (scaled, of course) and see when x=0, namely, when the line crosses the y-axis. That will be your answer. If you are looking for the formula way, here you go:

m=(4-0)/(10-(-10)) = 4/20 = 1/5

0 = 1/5(-10) + b
b= 2

y=x/5+2

Your y-intercept, or f(0), is 2

Answer 2

First you need to find the slope of the line using the slope equation, since you are given 2 points on the graph:
m=(y-y)/(x-x)
m= (0-4)/ (-10-10)
m=-4/-20 = 1/5

Now you can find the equation of the line using one of the points and the slope:
y-y=m(x-x)
y-4=1/5(x-10)
y=1/5x + 2

Now you can put any x point into that equation to get the corresponding y-value. So you want to evaluate f(0) which is the same as x=0, which is also the y-intercept.
So you get
y=1/5(0) +2
y=2
So f(0)=2

Answer 3

You need neither a graph nor algebra to solve this problem. A line is linear! Therefore, since the x-value required (i.e. 0) is the mean of the given x-values (-10 and +10), f(0), the value of the function at x=0, must be 2: the mean of 0 and 4.

Live long and prosper.

Answer 4

This is the formula of the straight line

y - y0 = [(y1-y0)/(x0-x1)] (x-x0)

The slope is m = (4-0)/(10-(-10)) = 4/20 = 1/5

So, y - y0 = m (x- x0), where x0 = -10 and y0 = 0

After you have found the equation, the independant term is the place where the straight line intersect the y axis, f(0)

Ana

Answer 5

m(x-x.)=y-y.
using the point(10,0)
m(x+10)=y................*1
m=(4-0)/[10-(-10)]
here m the slope equals 5
y=[(1/5)x]+2 from *1
f(x)=y
f(0)=2
hope it's true [-o<

Answer 6

4-0 over 10+10
m=1/5
0=(1/5)(-10)+b
0=-2+b
b=2
y=1/5x+2
y=(1/5)(0)+2
y=2