Chain rule Product rule Derivative

AI Thread Summary
To differentiate the expression (2x^2 - 3x + 1)(4x^3 + 4x - 3)^5, the product rule and chain rule are essential. The product rule states that the derivative of a product of two functions is the first function times the derivative of the second plus the second function times the derivative of the first. For the second function, (4x^3 + 4x - 3)^5, the chain rule is applied by letting u = (4x^3 + 4x - 3), leading to the derivative db/dx = 5u^4(du/dx). This approach allows for systematic differentiation of complex polynomial expressions. Understanding these rules is crucial for solving similar calculus problems effectively.
cj123
Messages
3
Reaction score
0

Homework Statement



(2x^2 - 3x + 1)(4x^3 + 4x -3)^5

Homework Equations





The Attempt at a Solution

 
Physics news on Phys.org
cj123 said:

The Attempt at a Solution


You might need to try this first





Do you know how differentiate single terms,products or quotients?
 
No, I have no problems like this in my notes. We have no textbook to refer back to.
 
Hint:
Topics covered:
Chain rule
Product rule
 
thanks for assisting, but I have no idea where to start on this type of problem.
 
ok I will put it in simple form:

(2x^2 - 3x + 1)(4x^3 + 4x -3)^5
a = (2x^2 - 3x + 1) b = (4x^3 + 4x -3)^5
so a*b

using product rule

a*db/dx + da/dx*b

and now
as b = (4x^3 + 4x -3)^5
make this b = (u)^5
so . db/dx = 5u^4.du/dx ...
 
I tried to combine those 2 formulas but it didn't work. I tried using another case where there are 2 red balls and 2 blue balls only so when combining the formula I got ##\frac{(4-1)!}{2!2!}=\frac{3}{2}## which does not make sense. Is there any formula to calculate cyclic permutation of identical objects or I have to do it by listing all the possibilities? Thanks
Since ##px^9+q## is the factor, then ##x^9=\frac{-q}{p}## will be one of the roots. Let ##f(x)=27x^{18}+bx^9+70##, then: $$27\left(\frac{-q}{p}\right)^2+b\left(\frac{-q}{p}\right)+70=0$$ $$b=27 \frac{q}{p}+70 \frac{p}{q}$$ $$b=\frac{27q^2+70p^2}{pq}$$ From this expression, it looks like there is no greatest value of ##b## because increasing the value of ##p## and ##q## will also increase the value of ##b##. How to find the greatest value of ##b##? Thanks
Back
Top