Quick Question: Write \frac{2\sqrt x+3}{x} in the Form 2x^p + 3x^q

  • Thread starter Thread starter _Mayday_
  • Start date Start date
AI Thread Summary
The discussion focuses on rewriting the expression \frac{2\sqrt{x}+3}{x} in the form 2x^p + 3x^q. Participants emphasize the importance of not multiplying by x to eliminate the denominator, as it alters the original expression. The correct approach involves separating the terms: 2\frac{\sqrt{x}}{x} + 3\frac{1}{x}, leading to the identification of p and q as -1/2 and -1, respectively. Clarifications on exponent rules are provided, ensuring that participants understand how to manipulate the expression correctly. The conversation concludes with participants confirming their understanding and the accuracy of their derived answers.
_Mayday_
Messages
808
Reaction score
0
[SOLVED] Quick Question

Hey!

This question may tex ability :shy:

The Question
Write \frac{2\sqrt x+3}{x} in the form 2x^p + 3x^q where p and q are constants.

Attempt :eek:

\frac{2\sqrt x+3}{x} \times x

2x + 3x

I basically multiplied the initial equation by x to get rid of the denominator, and now I have what looks like a close to correct answer, but without p and q, either p or q could be one but I think the fact that they have asked for p and q would suggest that they powers must be different.

Thanks to any helpers =]

_Mayday_
 
Physics news on Phys.org
Can you write 2\sqrt x/x in the form 2x^p?

Can you write 3/x in the form 3x^q?

Hint: don't multiply by x, this gives something different than what you started with (and are supposed to evaluate).
 
Heed Avodyne's advice! Say you were asked to reduce 64/8 and you decided to multiply by 8 to get rid of the denominator. You now have a different number. Don't confuse this with equations, where you can perform an operation to both sides (like division) and maintain the equality.
 
Avodyne said:
Can you write 2\sqrt x/x in the form 2x^p?

Can you write 3/x in the form 3x^q?

Hint: don't multiply by x, this gives something different than what you started with (and are supposed to evaluate).

x^{\frac{1}{2}}/x

3x^{-1}

I don't think I got the first bit correct...

Rashad9607 said:
Heed Avodyne's advice! Say you were asked to reduce 64/8 and you decided to multiply by 8 to get rid of the denominator. You now have a different number. Don't confuse this with equations, where you can perform an operation to both sides (like division) and maintain the equality.

Thanks
 
Basic algebra:
<br /> \frac{2\sqrt x+3}{x} = \frac{2\sqrt{x}}{x} + \frac{3}{x} = 2 \frac{\sqrt{x}}{x} + 3 \frac{1}{x}<br />
 
I have the 3 but now, but I am still struggling with the root x. Please try and explain how it works.

Thank you very much for your help so far though, my maths is actually quite good but I have these little cracks I need filling in...

Thanks again.
 
You are correct that \sqrt{3}= 3^{1/2}. Now what about the 1/x? What do the "laws of exponents" tell you about x^m/x^n?
 
Okay, I will take your post above as an example HallsofIvy? I tried looking for the root 3 but couldn't find it in my working! :smile:

I will take it that my answer is right:

x^\frac{1}{2}/x

which gives me...

x^\frac{1}{2} - x^{-1} = x^\frac {-1}{2}



Thanks Halls, I hope I am right...
 
_Mayday_ said:
Okay, I will take your post above as an example HallsofIvy? I tried looking for the root 3 but couldn't find it in my working! :smile:

I will take it that my answer is right:

x^\frac{1}{2}/x

which gives me...

x^\frac{1}{2} - x^{-1} = x^\frac {-1}{2}



Thanks Halls, I hope I am right...

Eh, your answer is right but oddly derived.

\frac{x^\frac{1}{2}}{x}=x^{\frac{1}{2}-1}=x^{\frac{-1}{2}}
 
  • #10
It was just a typo. He meant
x^{\frac{1}{2}}\times x^{-1}= x^{-\frac{1}{2}}
 
  • #11
I appreciate all of your help everyone, thankyou!

_Mayday_
 
Back
Top