Solving the limit of a function with no calculator

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  • #1
The Limx-->infinity of the function Square rt(5x^4+2x) / (x^2)

Note* The square root is only in the numerator for the expression (5x^4+2x)



I have tried multiplying by the complex conjugate but I am not sure if this is the correct way to do it.

I did sqrt(5x^4-2x) over itself and got sqrt 25x^8-4x / x^2

I had that as my answer, but my teacher told me this was incorrect. If anyone could help and explain that would be great! Thanks a lot!
 

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  • #2
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The Limx-->infinity of the function Square rt(5x^4+2x) / (x^2)

Note* The square root is only in the numerator for the expression (5x^4+2x)



I have tried multiplying by the complex conjugate but I am not sure if this is the correct way to do it.

I did sqrt(5x^4-2x) over itself and got sqrt 25x^8-4x / x^2

I had that as my answer, but my teacher told me this was incorrect. If anyone could help and explain that would be great! Thanks a lot!
Factor x4 out of both terms inside the radical, and bring this out as x2. You should be able to evaluate the limit then.
 
  • #3
Factor x4 out of both terms inside the radical, and bring this out as x2. You should be able to evaluate the limit then.
I'm not clear on what you mean by that. I understand factoring out the x^4 from the 5x^4 but not the 2x.
 
  • #4
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I'm not clear on what you mean by that. I understand factoring out the x^4 from the 5x^4 but not the 2x.
If you factor out x^4 from 2x, you are left with 2/x^3.
 
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