Differentiation problem square root function

In summary: The domain (plural) is the set of all possible values that the function can take. In this case, it's [-\sqrt{2}, \sqrt{2}].
  • #1
CrossFit415
160
0
I'm on mobile so I can't use latex.

Differentiate:

g(x)=√(4-x^4) , x is a set of [-√2, √2] and determine the domains.

So I got the derivative which is,

g'(x)=(-4x^3) ^1/2

What should I do with the -+√2 ?

I don't know what to do next
 
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  • #2
CrossFit415 said:
I'm on mobile so I can't use latex.

Differentiate:

g(x)=√(4-x^4) , x is a set of [-√2, √2] and determine the domains.

So I got the derivative which is,

g'(x)=(-4x^3) ^1/2
Nope. You need to use the chain rule. It will help to write your function as
g(x) = (4 - x4)^(1/2)
CrossFit415 said:
What should I do with the -+√2 ?

I don't know what to do next
 
  • #3
Alright
 
  • #4
I have

g'(x) = 1/2(4-x)^-1/2 • -4x^3

Then how would I determine the domains? I know 4-x^4 >= 0. So what about the two square roots?

What should I do with the +/-√2 ?
 
Last edited:
  • #5
It's still not right. Check your work.

Since your original is named g, its derivative is g', not G'.

The domain of g is the interval [-[itex]\sqrt{2}[/itex], [itex]\sqrt{2}[/itex]]. The domain of the this derivative will be exactly the same, with the possible exception of the endpoints.
 
  • #6
CrossFit415 said:
I have

G'(x) = 1/2(4-x)^-1/2 • -4x^3
NO. Do it again and show each step.

Then how would I determine the domains? I know 4-x^4 >= 0. So what about the two square roots?

What should I do with the +/-√2 ?
The domain will be the intersection of the natural domain of the derivative (not what you have above) and the given domain of the function, [itex][-\sqrt{2}, \sqrt{2}][/itex].
 
  • #7
g'(x) = 1/2(4-x^4)^1/2-1 • d/dx (4-x^4)
= 1/2(4-x^4)^-1/2 • -4x^3
Should I keep continuing?

Then
= -2x^3(4-x^4)^-1/2
 
Last edited:
  • #8
Please do NOT use "x" both as the variable and for multiplication!
 
  • #9
HallsofIvy said:
Please do NOT use "x" both as the variable and for multiplication!

Sorry!
 
  • #10
CrossFit415 said:
g'(x) = 1/2(4-x^4)^1/2-1 • d/dx (4-x^4)
= 1/2(4-x^4)^-1/2 • -4x^3
Should I keep continuing?

Then
= -2x^3(4-x^4)^-1/2
Much better.

When you write expressions on a single line, you need to use more parentheses. The above should be written as -2x^3(4-x^4)^(-1/2).
 
  • #11
Mark44 said:
Much better.

When you write expressions on a single line, you need to use more parentheses. The above should be written as -2x^3(4-x^4)^(-1/2).

Thanks! Ohh ok I ll be sure to use more parenthesis next time.

So should I just plug in +/- √2 for x to find the domains? Or leave it alone? Are the domains just +/- √2 ?
 
  • #12
CrossFit415 said:
So should I just plug in +/- √2 for x to find the domains? Or leave it alone? Are the domains just +/- √2 ?
Your question was answered twice in this thread.

I don't think you understand what "domain" means - it's not domains. The domain (singular) is the set of numbers at which the relevant function is defined.
 

Related to Differentiation problem square root function

1. What is the differentiation problem for a square root function?

The differentiation problem for a square root function involves finding the derivative of the square root function. This means finding the rate of change of the function at any given point on its graph.

2. How do you differentiate a square root function?

To differentiate a square root function, you can use the power rule, where n is the power of the function. For a square root function, n=1/2, so the derivative of the function is equal to 1/2 times the original function raised to the power of -1/2.

3. What is the domain and range of a square root function?

The domain of a square root function is all real numbers greater than or equal to 0, as the square root of a negative number is undefined. The range is also all real numbers greater than or equal to 0, as the square root of any number will always be a positive value.

4. How does the graph of a square root function change as you differentiate it?

The graph of a square root function will change from a curve to a straight line as you differentiate it. The slope of the line at any point on the graph will be equal to the derivative of the function at that point.

5. What are the practical applications of differentiating a square root function?

Differentiating a square root function can be used to find the instantaneous rate of change in situations where the dependent variable is related to the independent variable by a square root function. This can be useful in fields such as physics, engineering, and economics.

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