Question

Evaluate this function for x = 240.

Answer 1

For x=240, which of the three definitions will you use?

Answer 2

Is that what you're asking for?

Answer 3

whpalmer is asking...you have an 'x' ....x = 240

You have 3 different equations in that picture....

Which equation do you use...when you have x = 240?

Answer 4

x+5?

Answer 5

Right. What he said :-)

Look at the conditions to the right of each equation. Which one matches x=240?

Answer 6

Your x = 240

is your x

< 12 ?

>= 120 ?

or

< 120 and >= 12 ?

Answer 7

We use x+5 if x < 12. Is 240 < 12? No.

Answer 8

Oh 0.8x+5

Answer 9

Right....so now that you know which equation to use....you can plug in your 'x' value

You are using 0.8x + 5

your x = 240 so replace 'x' with 240

What does that equal...?

Answer 10

I get 197

Answer 11

As do I...that is correct

Answer 12

That makes three of us!

Answer 13

Thanks!

Answer 14

That's called a piecewise definition of a function, because each part describes a piece of the function.

Answer 15

Okay Thanks

Answer 16

For some functions, the pieces match up, so that the end value of one piece is equal to the nearby end value for the next piece. Such a function is continuous. Other times, there will be a bump in the road, so to speak, and that function will be discontinuous. This one is discontinuous because at 12 the piece to the left doesn't join up to the piece on the right.