Differentiate the function (derivatives, difference of sums rule)

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SUMMARY

The discussion focuses on differentiating the function f(x) = x^{1/2} - x^{1/3}. The correct derivative is calculated as f'(x) = 1/2x^{-1/2} - 1/3x^{-2/3}. Participants clarify the notation and provide insights on expressing negative exponents in terms of roots, emphasizing that x^{-1/2} can be rewritten as 1/√x and x^{-2/3} as 1/√[3]{x^2}. This understanding aids in simplifying the expression further.

PREREQUISITES
  • Understanding of basic calculus concepts, specifically differentiation.
  • Familiarity with exponent rules and their applications.
  • Knowledge of how to express negative exponents as fractions or roots.
  • Experience with functions and their derivatives.
NEXT STEPS
  • Study the rules of differentiation, particularly the power rule.
  • Learn how to simplify expressions involving negative exponents.
  • Explore the concept of derivatives in the context of real-world applications.
  • Practice differentiating more complex functions using the difference of sums rule.
USEFUL FOR

Students learning calculus, particularly those struggling with differentiation and exponent manipulation, as well as educators looking for effective teaching strategies in explaining these concepts.

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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.
 
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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:
Oh okay I think I understand. Thank you :)
 

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