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anonymous
 one year ago
Which of the following expressions represents a function?
A. x=1
B. {(3,2), (3, 2), (4, 5), (4,5)}
C. y= 4x1
D.4x^2+y^2=16
anonymous
 one year ago
Which of the following expressions represents a function? A. x=1 B. {(3,2), (3, 2), (4, 5), (4,5)} C. y= 4x1 D.4x^2+y^2=16

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anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Please help, I'm stuck!

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0In order for the expression to be a function, there must exist, for each value in the domain i.e. every xvalue, one and only one value in the range i.e. yvalue. Which one do you think it is?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0how can you tell a function from just a relation? hint: recall your DOMAIN and RANGE sets

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Ehhh I need a little more of a description on how to do it, I'm still confused

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0For every xvalue there is exactly one yvalue. For example {(0,1), (1,5), (0, 3), (2, 4)} is not a function because for the xvalue of 0, there are two yvalues, 1, and 3.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0I get it, so it's B!

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0By the example provided above, B cannot be a function because for the xvalues of 3 and 4, there is more than one associated yvalue. Check the others. What do you think?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0It couldn't be A? Because it's only a xvalue right? So that'd just leave C and D

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0That's right. For a the xvalue of 1 has an infinite number of yvalues. Check the others.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0I have a feeling that the answer is D, if that's right could you explain to me why please?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Let's look at D. Are you able to rearrange it to solve for y?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Not quite\[4x^2 + y^2 = 16\]\[y^2 = 16  4x^2\]\[y=\pm \sqrt{164x^2}\]Are you able to follow that?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0I don't really understand where you got the subtraction sign from when you first changed the equation. Can you explain what you did in this equation please?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0The goal is to isolate y. Therefore, in the first step, I subtracted 4x^2 from both sides of the equation. Then to solve for y, I took the square root of both sides. Make sense?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Yeah, so what does this tell us? That there is only a value for the y?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0OK. We've rearranged D to solve for y. So, choose an xvalue  0 would be a good choice. If you substitute 0 in for x, how many yvalues do you get?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.00 I guess? Sorry, I'm just not getting it as quickly as others probably would

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Take the rearranged equation D and substitute 0 in for x\[y=\pm \sqrt{164x^2}\]\[y=\pm \sqrt{164\left( 0 \right)^2}\]\[y= \pm \sqrt{16}\]What's the answer for y?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0You can do this. What's the square root of 16?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Right. So, in equation D, if x=0, then y has to be +4 or 4. There are two yvalues associated with x=0. Is this expression a function?

Mertsj
 one year ago
Best ResponseYou've already chosen the best response.0I think the square root of 16 is 4

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Ummmm, no...no it's not...

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0You're incorrect @Mertsj . The square root of 16 is 4.

Mertsj
 one year ago
Best ResponseYou've already chosen the best response.0Must be because (4)(4)=16

Mertsj
 one year ago
Best ResponseYou've already chosen the best response.0Maybe 16 has two square roots.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Anyways, yes, it does represent a function

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0You're screwing up this help session. There is a mathematical distinction between answering a) what number, when squared, equals 16 b) what is the square root of 16 The answer to the first question is =4 and 4 The answer to the second question is 5.

Mertsj
 one year ago
Best ResponseYou've already chosen the best response.0The square root of a number is a number which multiplied by itself, gives you the original number.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0The definition of a function is a relation in which, for every xvalue there is ONE AND ONLY ONE associated yvalue. We just determined that for x=0, there are two associated yvalues, +4 and 4. Therefore, this expression cannot be a function. Do you understand.

Mertsj
 one year ago
Best ResponseYou've already chosen the best response.0Here is an easier definition of a function: A function is a set of ordered pairs in which no two ordered pairs have the same first number.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0@Mertsj , what about {(1, 4), (3, 8), (1, 4), (1, 4)} ? You had better go back to school, chum.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0@Mertsj Oh dieses Zeug langweilt mich bis auf die Knochen .

Mertsj
 one year ago
Best ResponseYou've already chosen the best response.0(1,4) and (1,4) are not two ordered pairs. It is one ordered pair written down twice. If you write your name twice, does that make you two people?

Mertsj
 one year ago
Best ResponseYou've already chosen the best response.0@RavenDarkwood200 Me too.

Mertsj
 one year ago
Best ResponseYou've already chosen the best response.0@RavenDarkwood200 Wie kann der Blinde den Blinden führt

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0@Mertsj Worüber redest du? Ich verstehe nicht. Ich bin deutscher sehen Sie?
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