Differentiate the function (derivatives, difference of sums rule)

In summary, to differentiate f(x) = x^{1/2} - x^{1/3}, we use the power rule and get f'(x) = 1/2x^{1/2} - 1/3x^{2/3}. To avoid confusion, we can also write this as 0.5/\sqrt[]{x} - 0.333/\sqrt[3]{x^2}. The power of x can be rewritten as a root, for example x^{3/4} is the same as \sqrt[4]{x^3}.
  • #1
pbonnie
92
0

Homework Statement


Differentiate
[itex] f(x) = x^{1/2} - x^{1/3} [/itex]


Homework Equations


[itex] f(x) = f'(x)- g'(x)[/itex]


The Attempt at a Solution


I am a little stuck about what to do after the first couple steps. Here is my attempt.

[itex] f(x) = x^{1/2} - x^{1/3}[/itex]
[itex]f'(x) = (x^{1/2})' -(x^{1/3})'[/itex]
[itex]= 1/2x^{-1/2} - 1/3x^{-2/3}[/itex]
**** this is where I get confused *****
[itex]= 1/2x^{1/2} - 1/3x^{2/3}[/itex]
[itex]= ?[/itex]

Ps, I was recently told by a mentor not to write the prime in my solution, however, I'm leaving it like this because this is how it was taught in the course and I'm trying to avoid confusing myself further. Thank you.
 
Physics news on Phys.org
  • #2
wat is confusing about it? you got the right answer halfway through. how would you write x^-1/2? remember that x1/2 is of course [itex]\sqrt[]{x}[/itex]. so x-1/2 would be 1 over that: 1/[itex]\sqrt[]{x}[/itex]. same concept remember with x-1 = 1/x.

maybe the power of x is confusing you. remember that x3/4 for instance is the same as [itex]\sqrt[4]{x^3}[/itex].

so you could also write it as 0.5/[itex]\sqrt[]{x}[/itex] - 0.333/[itex]\sqrt[3]{x^2}[/itex]
 
Last edited:
  • #3
Oh okay I think I understand. Thank you :)
 

FAQ: Differentiate the function (derivatives, difference of sums rule)

What is the difference of sums rule in differentiation?

The difference of sums rule, also known as the subtraction rule or difference rule, is a mathematical rule used in differentiation to find the derivative of a function that is the difference of two other functions. It states that the derivative of the difference of two functions is equal to the difference of their individual derivatives.

How is the difference of sums rule used in real-world applications?

The difference of sums rule is used in various fields such as physics, engineering, and economics to calculate rates of change and optimize processes. For example, it can be used to find the maximum profit in an economic model or to calculate the velocity of a moving object.

Can the difference of sums rule be applied to more than two functions?

Yes, the difference of sums rule can be extended to any number of functions. This is known as the difference of sums general rule and states that the derivative of the difference of n functions is equal to the difference of their individual derivatives.

What is the difference between the difference of sums rule and the product rule?

The difference of sums rule is used to find the derivative of a function that is the difference of two or more functions, while the product rule is used to find the derivative of a function that is the product of two or more functions. In other words, the difference of sums rule is used for subtraction and the product rule is used for multiplication.

Are there any other rules for differentiation?

Yes, there are several other rules for differentiation, including the power rule, chain rule, quotient rule, and logarithmic and exponential rules. These rules are used to find the derivative of specific types of functions and can be combined with the difference of sums rule to solve more complex problems.

Similar threads

Replies
25
Views
1K
Replies
8
Views
713
Replies
1
Views
761
Replies
5
Views
968
Replies
2
Views
353
Replies
3
Views
779
Back
Top