Differentiation using product rule?

In summary, the conversation discusses differentiating a function using the product rule and general differentiation. The resulting solution is simplified by factoring out common factors.
  • #1
steve snash
50
0

Homework Statement


Differentiate the following function with respect to x,
p(x) = (( x+5 )^2)*(( x+3 )^7)


Homework Equations


well the product rule is,
p(x)=(f)*(g)
p'(x)= (f')*(g)+(g')*(f)
and general differentiation is,
p'(x)=n(f)^(n-1)*n(g)^(n-1)

The Attempt at a Solution


well i used the product rule and got
(2(x+5))*((x+3)^7)+(7(x+3)^6)*((x+5)^2)
but this is said to be wrong how do i simplify it more or what have i done wrong?
 
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  • #2
What you did is right. They probably just want you to pull out the common factors to simplify it more.
 
  • #3
so i could go,
(2*x+10)*(x+3)^7+(7x+21)*(x+5)^2
then
(3x+13)^7+(8x+26)^2
 
  • #4
steve snash said:
so i could go,
(2*x+10)*(x+3)^7+(7x+21)*(x+5)^2
then
(3x+13)^7+(8x+26)^2

Your algebra is looking pretty seriously awful there. Whoa. Just factor out (x+5)*(x+3)^6 and collect the rest. Try and use only real algebra this time, and not just random symbol rearrangment, ok?
 
  • #5
so it works out to be,
((x+3)^6)*((9x^2)+(86x)+205)
cheers for the help
 
  • #6
steve snash said:
so it works out to be,
((x+3)^6)*((9x^2)+(86x)+205)
cheers for the help

That's one version. You could also write it as (x+3)^6*(x+5)*(9x+1). Whatever works, like I said your initial differentiation was correct as well.
 

1. What is the product rule in differentiation?

The product rule is a formula used to find the derivative of a product of two functions. It states that the derivative of a product of two functions is equal to the first function multiplied by the derivative of the second function, plus the second function multiplied by the derivative of the first function.

2. When do we use the product rule in differentiation?

The product rule is used when we have a function that is a product of two or more other functions. This rule is particularly useful when finding the derivative of polynomial and trigonometric functions.

3. Can you provide an example of using the product rule in differentiation?

Yes, for example, if we have the function f(x) = x^2 * sin(x), we can use the product rule to find its derivative. The first function is x^2, and its derivative is 2x. The second function is sin(x), and its derivative is cos(x). Therefore, the derivative of f(x) is (x^2 * cos(x)) + (2x * sin(x)).

4. What is the purpose of using the product rule in differentiation?

The product rule allows us to find the derivative of a complicated function that is a product of two or more simpler functions. It is a fundamental rule in calculus and is essential for solving many real-world problems in physics, engineering, and economics.

5. Are there any other rules for finding derivatives?

Yes, there are other rules in calculus, such as the power rule, chain rule, and quotient rule, that help us find derivatives of different types of functions. These rules are all based on the fundamental principle of differentiation, and they are used to solve various problems in calculus.

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