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Author:  scc404 [ 14 Jan 2020, 17:58 ]
Post subject:  For each value of y greater than 2√3, the function f(x) is

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Question # 107, Date : 15-Jan-2020
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For each value of $$y$$ greater than $$2 \sqrt{3}$$, the function $$f(x)$$ is such that the equation $$f(x) = y$$ has a solution of the form $$x=\frac{y^2+12}{y}$$

Select one value for $$a$$ and one value for $$b$$ such that the given information implies $$f(a) = b$$. Make only two selections, one in each column.

 $$a$$ $$b$$ Values 1 2 4 6 8

Show SpoilerMy Question
Need help with this question. I don't understand how you know that because y is greater than $$2 \sqrt{3}$$, then only choices available for $$b$$ are 4, 6, and 8. How do you know that from "greater than $$2 \sqrt{3}$$"?

B: 6
A: 8

Author:  CAMANISHPARMAR [ 14 Jan 2020, 22:46 ]
Post subject:  Re: For each value of y greater than 2√3, the function f(x) is

scc404 wrote:
Project IR Butler 2019-20 - Get one IR Question Everyday
Question # 107, Date : 15-Jan-2020
This post is a part of Project IR Butler 2019-20. Click here for Details

For each value of $$y$$ greater than $$2 \sqrt{3}$$, the function $$f(x)$$ is such that the equation $$f(x) = y$$ has a solution of the form $$x=\frac{y^2+12}{y}$$

Select one value for $$a$$ and one value for $$b$$ such that the given information implies $$f(a) = b$$. Make only two selections, one in each column.

 $$a$$ $$b$$ Values 1 2 4 6 8

Show SpoilerMy Question
Need help with this question. I don't understand how you know that because y is greater than $$2 \sqrt{3}$$, then only choices available for $$b$$ are 4, 6, and 8. How do you know that from "greater than $$2 \sqrt{3}$$"?

$$2 \sqrt{3}$$ is less than 4 because $$\sqrt{3}$$ is less than 2.

Hence:
a = 8 and b = 6

 Author: scc404 [ 15 Jan 2020, 18:08 ] Post subject: Re: For each value of y greater than 2√3, the function f(x) is doesn't that mean it has to be greater than 2 because it is 2 and a root which leaves the other numbers? I'm still confused by that.

 Author: CAMANISHPARMAR [ 15 Jan 2020, 20:53 ] Post subject: Re: For each value of y greater than 2√3, the function f(x) is scc404 wrote:doesn't that mean it has to be greater than 2 because it is 2 and a root which leaves the other numbers? I'm still confused by that.Could you please elaborate more on your question; I have not understood it.

 Author: lacabral [ 16 Jan 2020, 08:39 ] Post subject: Re: For each value of y greater than 2√3, the function f(x) is I am confused as to how we got b=4. If I plug in 4 for "b", the answer is 7. However, if I plug in a=4, and b=6, the answer becomes f(4)=4. Where did I go wrong?

 Author: CAMANISHPARMAR [ 17 Jan 2020, 20:56 ] Post subject: Re: For each value of y greater than 2√3, the function f(x) is lacabral wrote:I am confused as to how we got b=4. If I plug in 4 for "b", the answer is 7. However, if I plug in a=4, and b=6, the answer becomes f(4)=4. Where did I go wrong?You may be right, I did not like the question so much. Did you mean to say "a = 8 and NOT 4"? b = 6 seems to be ok. kindly show your calculations.

 Author: lacabral [ 18 Jan 2020, 04:14 ] Post subject: Re: For each value of y greater than 2√3, the function f(x) is CAMANISHPARMAR wrote:lacabral wrote:I am confused as to how we got b=4. If I plug in 4 for "b", the answer is 7. However, if I plug in a=4, and b=6, the answer becomes f(4)=4. Where did I go wrong?You may be right, I did not like the question so much. Did you mean to say "a = 8 and NOT 4"? b = 6 seems to be ok. kindly show your calculations.Yes! Correct, I meant to type a=8, b=6. Thank you so much!

 Author: Sajjad1994 [ 23 Apr 2021, 03:53 ] Post subject: Re: For each value of y greater than 2√3, the function f(x) is Official ExplanationThe formula may only be applied for y greater than $$2\sqrt{3}$$, therefore, the only choices available for b are 4, 6, and 8.If f(a) = b and b = 4, then, according to the formula,$$a=\frac{4^2+12}{4}=\frac{28}{4}=7$$Since 7 is not an option, b = 4 must not be part of the correct response.If f(a) = b and b = 6, then, according to the formula,$$a=\frac{6^2+12}{6}=\frac{48}{6}=8$$Since 8 is an option, a = 8 and b = 6 must be the correct response.The correct answer is 8.The correct answer is 6.

 Author: MichaelWunsch [ 25 Apr 2021, 21:48 ] Post subject: Re: For each value of y greater than 2√3, the function f(x) is I am confused as to how we got b=4

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