Differentiating (v^3-2v*squareroot v): A Try

In summary: Just remember that when you have a fraction, you can always cancel out common factors from the numerator and denominator to simplify it. In summary, the conversation discusses how to differentiate a complex expression involving a square root and the application of the power rule and chain rule. The conversation also touches on the use of the quotient rule, but ultimately simplifies the expression to make differentiation easier.
  • #1
Altami
17
0

Homework Statement


How would you differentiate, (v^3-2v*squareroot v)?


Homework Equations





The Attempt at a Solution



would it look like...3v^2 - v^-1/2 ?
 
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  • #2
Altami said:
would it look like...3v^2 - v^-1/2 ?

The 3v^2 part is correct! But how did you obtain v^-1/2??
 
  • #3
micromass said:
The 3v^2 part is correct! But how did you obtain v^-1/2??

Ah, see that's the thing how to you differentiate a square root? I have no idea?
 
  • #4
Well, [tex]\sqrt{x}=x^{1/2}[/tex], so you just need to apply the power rule!

But the problem is that you don't only have a square root, you have [tex]v\sqrt{v}[/tex]. To derive this, you have to apply the chain rule. (or if you know your algebra, you could notice that [tex]v^{3/2}=v\sqrt{v}[/tex] and immediately apply the power rule)...
 
  • #5
micromass said:
Well, [tex]\sqrt{x}=x^{1/2}[/tex], so you just need to apply the power rule!

But the problem is that you don't only have a square root, you have [tex]v\sqrt{v}[/tex]. To derive this, you have to apply the chain rule. (or if you know your algebra, you could notice that [tex]v^{3/2}=v\sqrt{v}[/tex] and immediately apply the power rule)...

Well okay, I wanted to see if by understanding how to derive squareroot v, I could understand a much bigger problem.

The actual problem that is connected is this

y=(v^3 - 2v*square rootv)/ v

and I have to differentiate it, I know I have to use the quotient rule and I have tired but the dang square root is cause me problems.
 
  • #6
Can't you just cancel v from the numerator and denominator??
 
  • #7
micromass said:
Can't you just cancel v from the numerator and denominator??

I don't think so, I haven't tried that I know the answer...because it is...(2v-1)/squareroot2

But I don't know how to get to that, I've tried everything...that I know of...and I still can't get that answer...
 
  • #8
so if someone could show me? maybe a step by step...cause I have wasted a while on this one problem...
 
  • #9
So, nobody has an idea?
 
  • #10
Altami said:
y=(v^3 - 2v*square rootv)/ v

and I have to differentiate it, I know I have to use the quotient rule and I have tired but the dang square root is cause me problems.

No, you don't have to use the quotient rule if you simplify this first.

[tex]y = \frac{v^3 - 2v\sqrt{v}}{v} = v^2 - 2\sqrt{v} = v^2 - 2v^{1/2}[/tex]
 
  • #11
Mark44 said:
No, you don't have to use the quotient rule if you simplify this first.

[tex]y = \frac{v^3 - 2v\sqrt{v}}{v} = v^2 - 2\sqrt{v} = v^2 - 2v^{1/2}[/tex]

How can I vote you to be a life saver? Thank you so much, for some reason my teacher told me I HAD to use the quotient rule and I guess that blocked me to thinking of other ways! Thank you so much, your a life saver!
 
  • #12
Well, if the instructions are that you have to use the quotient rule, then I haven't been any help at all. If so, I would write the numerator as v3 - 2v3/2.
 
  • #13
Mark44 said:
Well, if the instructions are that you have to use the quotient rule, then I haven't been any help at all. If so, I would write the numerator as v3 - 2v3/2.

Well, I meant that he didn't really give us clues as to have other ways of solving them, your were a great help. I still had to differentiate the final answer which you gave me, but I was able to do that no problem. Thank you anyways, again you did help me.
 
  • #14
Sure, you're welcome.
 

FAQ: Differentiating (v^3-2v*squareroot v): A Try

What is differentiation?

Differentiation is a mathematical process used to find the rate of change of a function with respect to its input variables. It involves calculating the derivative of a function, which gives the slope of the function at a specific point.

What is the purpose of differentiating?

The main purpose of differentiation is to analyze the behavior of a function and understand how it changes over its input variables. It is also used to find maximum and minimum values of a function, and to solve optimization problems in various fields such as physics, economics, and engineering.

What is the general formula for differentiating a function?

The general formula for differentiating a function f(x) is given by f'(x) = lim (h->0) [f(x+h) - f(x)] / h. This can also be written as f'(x) = df(x)/dx.

Can you differentiate a function with multiple variables?

Yes, differentiation can be done on functions with multiple variables, such as f(x,y,z). In this case, partial derivatives are used to find the rate of change of the function with respect to each of its variables.

How do you differentiate a function with a radical term?

To differentiate a function with a radical term, such as v^3 - 2v*squareroot(v), we can use the power rule for differentiation, which states that the derivative of x^n is nx^(n-1). In this case, the derivative of v^3 would be 3v^2, and the derivative of 2v*squareroot(v) would be 2(v^(1/2))(1) + (2v)(1/2)(v^(-1/2)) = (2v^(1/2)) + (v^(-1/2)). Therefore, the derivative of the given function would be 3v^2 - (2v^(1/2)) - (v^(-1/2)).

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