Solving Expressions: Factor a^2-b^2 and a^3-b^3

  • Thread starter Thread starter Gus_Chiggins
  • Start date Start date
  • Tags Tags
    Formulas
Gus_Chiggins
Messages
3
Reaction score
0
Part 1:Factor the expressions a^2-b^2 and a^3-b^3

For part 1, i worked it out to be:
(a+b)(a-b) and (a-b)(a^2+ab+b^2)

Part 2: Suppose f(x) is a function that has a derivative. Let g(x)=x^2f(x), k(x)=\sqrt{f(x)}, and p(x)=^3\sqrt{f(x)}. Without using the product rule and w/o using the chain rule, find formulas for g'(a), k'(a), and p'(a) in terms of a, f(a) and f'(a)

Any help would be great for part 2. I really don't know how to tackle this problem. Thanks!
 
Physics news on Phys.org
There was no restriction on using the limit definition of the derivative. I think that might be where they're trying to steer you, especially with the problem in part 1.
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
Back
Top