What is the Chain Rule for Differentiating tan^3(x) + tan(x^3)?

In summary, the derivative of tan^3(x) + tan(x^3) is equal to 3tan^2(x)sec^2(x) + 3x^2sec^2(x^3). The first term is calculated using the chain rule, while the second term is calculated using the derivative of the function g(x) = x^3 and f(x) = tan(x). The correct derivative of tan(x^3) is 3x^2sec^2(x^3).
  • #1
delfam
34
0

Homework Statement



tan^3(x) + tan(x^3)

Homework Equations





The Attempt at a Solution



tan^3(x) + sec^2(x^3) + 3x^2


Im not sure how to do the tan^3(x) and not even sure I did the tan(x^3) right
 
Physics news on Phys.org
  • #2
the first term is as follows
[tex] \frac{d}{dx} (tan(x))^3 = 3 tan^2(x)\frac{d (tan(x))}{dx} =..[/tex]

here assume you have
[tex] g(x) = x^3 [/tex]
[tex] f(x) = tan(x) [/tex]

and you know
[tex] g(x) = 3x^2 [/tex]
[tex] f(x) = sec(x) [/tex]

in this form it becomes
[tex] g(f(x)) = (tan(x))^3 =..[/tex]

[tex]\frac{d}{dx} g(f(x)) = g'(f(x))f'(x) = ...[/tex]

finish this & try the 2nd term again as its not correct either
 
  • #3
expanded above
 

1. What is the chain rule in calculus?

The chain rule is a rule used in calculus to find the derivative of a composite function. It is used when a function is composed of two or more functions, and allows us to find the rate of change of the outer function with respect to the rate of change of the inner function.

2. Why is the chain rule important?

The chain rule is important because it allows us to find the derivative of more complex functions, which are often used in real-world applications. It is also a fundamental rule in calculus, and is necessary for understanding more advanced concepts such as multivariable calculus and differential equations.

3. How do you use the chain rule?

To use the chain rule, you must first identify the outer and inner functions of the composite function. Then, you take the derivative of the outer function and multiply it by the derivative of the inner function. This can be represented mathematically as (f(g(x)))' = f'(g(x)) * g'(x), where f(x) is the outer function and g(x) is the inner function.

4. Can you provide an example of using the chain rule?

Sure, let's say we have the function f(x) = (x^2 + 1)^3. To find the derivative of this function, we can first identify the outer function as (x^2 + 1)^3 and the inner function as x^2 + 1. Then, we take the derivative of the outer function, which is 3(x^2 + 1)^2, and multiply it by the derivative of the inner function, which is 2x. This gives us the final derivative of f(x) as 3(x^2 + 1)^2 * 2x = 6x(x^2 + 1)^2.

5. Are there any common mistakes when using the chain rule?

Yes, some common mistakes when using the chain rule include forgetting to take the derivative of the outer function, incorrectly multiplying the derivatives of the inner and outer functions, and not correctly identifying the inner and outer functions. It is important to carefully follow the steps and practice solving various problems to avoid these mistakes.

Similar threads

  • Calculus and Beyond Homework Help
Replies
5
Views
1K
  • Calculus and Beyond Homework Help
Replies
3
Views
335
  • Calculus and Beyond Homework Help
Replies
8
Views
753
  • Calculus and Beyond Homework Help
Replies
10
Views
933
  • Calculus and Beyond Homework Help
Replies
2
Views
907
  • Calculus and Beyond Homework Help
Replies
2
Views
591
  • Calculus and Beyond Homework Help
Replies
15
Views
1K
  • Calculus and Beyond Homework Help
Replies
2
Views
238
  • Calculus and Beyond Homework Help
Replies
3
Views
784
  • Calculus and Beyond Homework Help
Replies
5
Views
715
Back
Top