# Math Is Fun Forum

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## #1 2021-04-11 06:54:54

mathland
Banned
Registered: 2021-03-25
Posts: 438

### Rate of Change of Linear Function

Show that the rate of change of a linear
function f (x) = mx + b is the slope m of the line y = mx + b.

Can someone get me started here?

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## #2 2021-04-11 19:24:41

Bob
Registered: 2010-06-20
Posts: 9,128

### Re: Rate of Change of Linear Function

This also can be done using calculus or you could try this:

Write down the coordinates of two points on the line (x1,y1) and (x2,y2) and compute

difference in y coords divided by difference in x coords.

Bob

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

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## #3 2021-04-12 10:03:31

mathland
Banned
Registered: 2021-03-25
Posts: 438

### Re: Rate of Change of Linear Function

Bob wrote:

This also can be done using calculus or you could try this:

Write down the coordinates of two points on the line (x1,y1) and (x2,y2) and compute

difference in y coords divided by difference in x coords.

Bob

What are the specific coordinates of the two points?

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## #4 2021-04-12 19:51:31

Bob
Registered: 2010-06-20
Posts: 9,128

### Re: Rate of Change of Linear Function

In order to keep the algebra as simple as possible, replace y1 with mx1 + c, and y2 with mx2 + c

Bob

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

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## #5 2021-04-14 11:53:56

mathland
Banned
Registered: 2021-03-25
Posts: 438

### Re: Rate of Change of Linear Function

Bob wrote:

In order to keep the algebra as simple as possible, replace y1 with mx1 + c, and y2 with mx2 + c

Bob

Hello Bob. I will play with this some more. By the way, do you know if there are math websites where tutors provide a complete solution to questions (regardless of topic and level of questions) for free or for a small fee?

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## #6 2021-04-14 20:16:54

Bob
Registered: 2010-06-20
Posts: 9,128

### Re: Rate of Change of Linear Function

Other than MIF, no I don't.  The Khan Academy has some U-tube videos but you cannot specify what you want to see next.  Our own zetafunc has a U Tube channel that teaches some advanced topics.  zetafunc might create a video for you on a topic if you ask him.

Bob

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

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## #7 2021-04-15 14:23:08

mathland
Banned
Registered: 2021-03-25
Posts: 438

### Re: Rate of Change of Linear Function

Bob wrote:

Other than MIF, no I don't.  The Khan Academy has some U-tube videos but you cannot specify what you want to see next.  Our own zetafunc has a U Tube channel that teaches some advanced topics.  zetafunc might create a video for you on a topic if you ask him.

Bob

Thanks anyway. What do you think about the Photomath app?
Take a picture of any equation and ot provides a step by step solution.
Wish there was an app like Photomath for word problems.

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