Domain and Functions | Mathematics | Page 1

fallow prawnBOT Jul 15, 2024, 5:00 PM

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languid kiln Jul 15, 2024, 5:02 PM

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The range is the set of values of y.
So, for each value of y, solve y = 5x - 2 for x. That will give you the domain.

green pewter Jul 15, 2024, 5:02 PM

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darpinger helping me altho its not my question

languid kiln Jul 15, 2024, 5:03 PM

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green pewter darpinger helping me altho its not my question

Please don't invade into other people's posts. Make your own.

green pewter Jul 15, 2024, 5:03 PM

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dude u alr helped me so i dont need to lol

ripe pivot Jul 15, 2024, 5:03 PM

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languid kiln The range is the set of values of y. So, for each value of y, solve y = 5x - 2 f...

Yes, i get that but the answer for this is The domain is {2, 3, 4}

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how do I get 2 3 and 4

languid kiln Jul 15, 2024, 5:04 PM

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ripe pivot how do I get 2 3 and 4

As I said, express x from y = 5x - 2, then substitute the values of y from the domain.

ripe pivot Jul 15, 2024, 5:05 PM

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I'm so sorry, can you write out the steps I still don't follow.

languid kiln Jul 15, 2024, 5:06 PM

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ripe pivot I'm so sorry, can you write out the steps I still don't follow.

Do you know how to solve linear equations? Say, of the form ax + b = c.

ripe pivot Jul 15, 2024, 5:07 PM

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Yes.

languid kiln Jul 15, 2024, 5:07 PM

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Well, think of y = 5x - 2 as a linear equation, and solve for x.

ripe pivot Jul 15, 2024, 5:11 PM

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I'm so sorry, can you write out the steps I still don't follow.

languid kiln Jul 15, 2024, 5:12 PM

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ripe pivot I'm so sorry, can you write out the steps I still don't follow.

You said that you know how to solve ax + b = c for x. What will the solution be?

ripe pivot Jul 15, 2024, 5:12 PM

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Using inverse operations correct?

languid kiln Jul 15, 2024, 5:12 PM

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Well, yes.

ripe pivot Jul 15, 2024, 5:13 PM

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I got 0.4

languid kiln Jul 15, 2024, 5:13 PM

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Not sure what you did, but I meant an expression for x in terms of y.

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Well, let's look at our expression: y = 5x - 2. For convenience, let's switch sides:
5x - 2 = y
We want to express x. What should we do first?

ripe pivot Jul 15, 2024, 5:15 PM

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add 2 to both sides

languid kiln Jul 15, 2024, 5:15 PM

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Right. What do we get?

ripe pivot Jul 15, 2024, 5:15 PM

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5x = 2y

languid kiln Jul 15, 2024, 5:16 PM

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No. You multiplied the RHS by 2, while you should've added 2 instead.

ripe pivot Jul 15, 2024, 5:17 PM

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5x = y + 2

languid kiln Jul 15, 2024, 5:17 PM

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Yeah, nice! What next?

ripe pivot Jul 15, 2024, 5:18 PM

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I'm not sure, normally it would stop here because you can't simplify further.

languid kiln Jul 15, 2024, 5:19 PM

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Well, what should you do to 5x to make it x?

ripe pivot Jul 15, 2024, 5:19 PM

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divide it by 5

languid kiln Jul 15, 2024, 5:20 PM

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Yeah. So, we can divide both sides by 5.

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Which results in x = (y + 2)/5.

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So, we've expressed x. Now, for each value of y in the range of the function find the respective value of x. The set of those values would be the domain of the function.

ripe pivot Jul 15, 2024, 5:21 PM

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Ok, I understand now! Thank you!

languid kiln Jul 15, 2024, 5:22 PM

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Nice, you're welcome!

#Domain and Functions