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need step by step instructions for this math answerf(x) =x^2-x-6

 

Customer Question

need step by step instructions for this math answer
f(x) =x^2-x-6 g(x)= the square root of √x/x
h(x)=g(f(x))
Then represent the domain on a number line and give the rereasons why. How do you know if it is open or closed?
how do you know if arrows go into the opposite direction on number line?... and so on. please

Submitted: 290 days and 5 hours ago.
Category: Pre-Calculus
Value: $14
Status: CLOSED

Accepted Answer

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Expert:  Trigeoscal replied 290 days and 4 hours ago.

Thank you for choosing Justanswer.com

I will be posting the answers in a few minutes




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Expert TypeMaster's Degree
Category: Pre-Calculus
Pos. Feedback: 90.9 %
Accepts: 84
Answered: 7/1/2012

Experience: Mathematics, Calculus and Stat

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Expert:  Trigeoscal replied 290 days and 4 hours ago.

This is a composite functions, since the given are


f(x) =x^2-x-6 g(x)= the square root of √x/x
h(x)=g(f(x))

then

h(x) = √(x^2-x-6) / (x^2-x-6) or h(x) = 1 / √(x^2-x-6)

To find the domain of h(x), since h(x) is a combination of radical function and rational function, we need to find the zeroes of the function inside the radical that is , find the zeroes of f(x)

using factoring f(x) = x^2-x-6

x^2-x-6 = 0

(x - 3)(x + 2) = 0

x = 3 or x = -2

so the possible regions are -2 < x 3 or x 3 or x 3 or x < -2

using Numberline, the domain will be






-5 -4 -3 -2 -1 0 1 2 3 4 5


(note again: please disregard the dots above the interval between -2 and 3, since there should not be any dots there)

To know if it is an open or close interval, try substituting a value between the two boundaries, so between -2 and 3, try substituting any value, let us say, zero, if the value of h(x) is real number, then it is a closed interval, otherwise, it is an open interval


Similarly if the interval is open, then the arrows should be away, directed to left and right (to + and - infinity) but if the interval is closed, there are no arrows)



Please Leave a POSITIVE FEEDBACK to Credit me. BONUS is welcome.Thanks.

If you need my help asap, just write in the first part of your question: "For Mr Glenn G. only!" Thanks again

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Expert:  Trigeoscal replied 290 days and 4 hours ago.

Here are the answers



http://www.mediafire.com/view/?yftofl8zdxkzyd4




Please Leave a POSITIVE FEEDBACK to Credit me. BONUS is welcome.Thanks.

If you need my help asap, just write in the first part of your question: "For Mr Glenn G. only!" Thanks again


Thanks again Dont forget to accept my answers if you are satisfied, so that I will be compensated in helping you, thanks again!

Customer replied 290 days and 3 hours ago.

I will accept ... but I would like to know exactly how it goes from the given to 1/√(x²-x-6)/

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Expert:  Trigeoscal replied 290 days and 3 hours ago.

hello!

just a clarification

is the correct given is


g(x)= the square root of √x/x

or

g(x)= (the square root of x)/x

Customer replied 290 days and 3 hours ago.

g(x)=√(x)/x is the correct form i am sorry i forgot to delete the words "square root" from the originally posted problem.

I am just not understanding how h(x)=√(x²-x-6)/x²-x-6 goes to 1/√(x²-x-6)

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Expert:  Trigeoscal replied 290 days and 3 hours ago.

ah ok, here are the step by step solutions


if(x) =x^2-x-6 g(x)= √x/x
h(x)=g(f(x))


example: f(x) = 2x + 1, g(x) = √x, and h(x) = g(f(x))

then since f(x) is inside g(x), we put f(x) = 2x + 1, inside g(x), thus

h(x) = g(f(x))

h(x) = g(2x + 1)

h(x) = √(2x + 1)

similarly


if(x) = x^2-x-6 g(x)= √x/x
h(x)=g(f(x))


then putting or substituting x^2-x-6 for x in g(x)= √x/x, then

g(x)= √x/x --> g(x^2-x-6)= √(x^2-x-6)/(x^2-x-6)


thus h(x) = √(x^2-x-6)/(x^2-x-6)


(note: that √2/2 is also the same as 1 / √2, similarly, √5/5 = 1/√5)

and so √(x^2-x-6)/(x^2-x-6) = 1/ √(x^2-x-6)



Please Leave a POSITIVE FEEDBACK to Credit me. BONUS is welcome.Thanks.

If you need my help asap, just write in the first part of your question: "For Mr Glenn G. only!" Thanks again


Thanks again Dont forget to accept my answers if you are satisfied, so that I will be compensated in helping you, thanks again!

Customer replied 290 days and 2 hours ago.

THANK YOU!!!

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Expert:  Trigeoscal replied 290 days and 2 hours ago.

you are welcome



Please Leave a POSITIVE FEEDBACK to Credit me. BONUS is welcome.Thanks.

If you need my help asap, just write in the first part of your question: "For Mr Glenn G. only!" Thanks again


Thanks again Dont forget to accept my answers if you are satisfied, so that I will be compensated in helping you, thanks again!

Customer replied 290 days and 2 hours ago.

I accepted... but I am stuck on this:
could write it... as if you were teaching what it means

so the possible regions are -2 < x 3 or x 3 or x 3 or x < -2

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Expert:  Trigeoscal replied 290 days and 2 hours ago.

here they are so the possible regions are x < 3 and x > -2


or x < -2 or x > 3


to test which among the two possible intervals are correct? try to substitute any number between -2 and -3, let us say zero



Please Leave a POSITIVE FEEDBACK to Credit me. BONUS is welcome.


Thanks.
If you need my help asap, just write in the first part of your question: "For Mr Glenn G. only!"


Thanks again
Thanks again Dont forget to accept my answers if you are satisfied, so that I will be compensated in helping you, thanks again!
Glenn Gilongos41092.0502003472

 
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