Product Rule Homework: Find (fg)'(2)

In summary, to find (fg)'(2), we use the product rule which states that (fg)'(x) = f'(x)g(x) + g'(x)f(x). Then, we substitute the given values to find (fg)'(2) = f'(2)g(2) + g'(2)f(2). We can then solve for the value of (fg)'(2).
  • #1
HerroFish
20
0

Homework Statement


If f(2) = 3, f'(2) = 5, g(2) = -1, g'(2) = -4, find (fg)'(2).


Homework Equations


if F(x) = f(x)g(x)
F'(x) = f'(x)g(x) + g'(x)f(x)

The Attempt at a Solution


I have no idea how to attempt his question :(
 
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  • #2
HerroFish said:

Homework Statement


If f(2) = 3, f'(2) = 5, g(2) = -1, g'(2) = -4, find (fg)'(2).


Homework Equations


if F(x) = f(x)g(x)
F'(x) = f'(x)g(x) + g'(x)f(x)

The Attempt at a Solution


I have no idea how to attempt his question :(
So you know the product rule:
(fg)'(x) = f'(x)g(x) + g'(x)f(x)

You want to find (fg)'(2), which equals...
(fg)'(2) = f'(2)g(2) + g'(2)f(2)

You can figure out the rest.
 
  • #3
you've got the answer right in front of you they are asking F' ' (2) = (fg) ' (2) so what is (fg)' ?
 

FAQ: Product Rule Homework: Find (fg)'(2)

1. What is the product rule?

The product rule is a mathematical rule used to find the derivative of a product of two functions. It states that the derivative of the product of two functions is equal to the first function times the derivative of the second function plus the second function times the derivative of the first function.

2. How do you use the product rule to find (fg)'(2)?

To find (fg)'(2), we first need to identify the two functions, f and g. Then, we apply the product rule by taking the derivative of each function and plugging them into the formula (f'g + fg'). Finally, we substitute the value of 2 into the resulting equation to find the value of (fg)'(2).

3. What is the significance of finding (fg)'(2)?

Finding (fg)'(2) allows us to determine the rate of change of a product of two functions at a specific point, which can be useful in many fields such as physics, engineering, and economics. It also helps us to understand the behavior of the functions and make predictions about their future values.

4. Can you provide an example of using the product rule to find (fg)'(2)?

Sure, let's say we have the two functions f(x) = 2x and g(x) = x^2. Using the product rule, we have (fg)'(x) = f'(x)g(x) + f(x)g'(x). Plugging in the values, we get (fg)'(x) = 2x(x^2) + 2x(2x) = 4x^2 + 4x. So, (fg)'(2) = 4(2)^2 + 4(2) = 20.

5. Are there any other rules that can be used to find derivatives?

Yes, there are several other rules such as the power rule, quotient rule, and chain rule that can be used to find derivatives of various functions. It is important for a scientist to be familiar with all of these rules and know when to apply them in order to solve complex problems.

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