Functions

Today in class we went further into functions. We wer given a function and had to come up with a domane and range for it. To make the function more accurate on a graph you want to make the value of x be both positive and negative numbers. When you come up with your x values you simply put them into ur equation to find what the function of x or f(x) equals.

EXAMPLE: f(x)=4(x)+3
f(-5)=4(-5)+3 x f(x)
-5 -17 f(-5)=-20+3

f(-5)=-17 -1
1
5
Then you would finish all the numbers by doing the same thing and subsituting your x values for x in the equation and your outcome is f(x) or y on the graph. The example done for you would be at the point -5, -17 on a graph.

complete example: f(x)=5x-1 x f(x)
-6 -31
-1 -6
0 -1
1 4
6 29

Also, we were given a domain and a range and asked to find the function. When finding the funcion, alway check your idea on every x, f(x) pair before writing the function for your chart.

EXAMPLES: x f(x) funtion- f(x)=x(4) x f(x)
2 x4 8 2 5
4 x4 16 5 11
5 x4 20 11 23
8 x4 32 23 47

When you are looking for the function it isn't always just one step funtions making them more tricky like the second one. The function is f(x)=2(x)+1.

The other problems we did today were very similar to those in our MSA unit. For these you had to relate, define, and write.

EXAMPLES: Mark recently started a snow shoveling company. He spent $20 on two new shovels and $50 on salt to last the season meaning he put $70 into his business. For each yard he charges $30. Write a fanction to show Mark's profit.

relate- 30 dollars per yard-70 dallars=profit
define- y= yard
p=profit
write- 30(y)-70=p

If mark shovels 5 yards his profit will be 80 dollars. Just like when you find the range of a function you plug your value into the equation.