Question

Explain how to write function rule from the table below. Then write a function rule. x=0,2,4,6. y=2,1,0,-1

Answer 1

How did you find that 2 was equal to b?

Answer 2

To write a function rule from a table, we need to identify how the output (y) is related to the input (x). One way to do this is to find the pattern or relationship between the values in each column.

Looking at the table, we can see that as x increases by 2, y decreases by 1. In other words, the rate of change between x and y is -1/2, meaning that for every 2-unit increase in x, y decreases by 1 unit.

Using this information, we can write a function rule in the form y = mx + b, where m is the slope (rate of change) and b is the y-intercept (the value of y when x is 0). To find m, we use the rate of change we identified earlier: m = -1/2. To find b, we can use any point on the line. We'll use the first point (x = 0, y = 2):

y = mx + b
2 = (-1/2)(0) + b
2 = b

So our function rule is:

y = -1/2x + 2

Answer 3

To find the value of b, we need to use the y-intercept of the line, which is the value of y when x is 0. We can use any point on the line to find the value of b, but it is often easiest to use the point where x = 0, since the x-coordinate is already 0 and we only need to find the y-coordinate.

In this case, we use the first point given in the table: x = 0, y = 2. Plugging these values into the equation y = mx + b, we get:

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

Since multiplying anything by 0 gives 0, the right side of the equation simplifies to:

2 = b

So we have found that the value of b is 2. Therefore, the function rule for the table is:

y = -1/2x + 2