# AP Calculus AB : Understanding the derivative of trigonometric functions

## Example Questions

### Example Question #4 : Specific Derivatives

Find the derivative of the following function:

Explanation:

The derivative of  is. It is probably best to memorize this fact (the proof follows from the difference quotient definition of a derivative).

Our function

the factor of 3 does not change when we differentiate, therefore the answer is

### Example Question #5 : Specific Derivatives

Explanation:

The derivative of a sine function does not follow the power rule. It is one that should be memorized.

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### Example Question #6 : Specific Derivatives

What is the second derivative of ?

Explanation:

The derivatives of trig functions must be memorized. The first derivative is:

.

To find the second derivative, we take the derivative of our result.

.

Therefore, the second derivative will be .

### Example Question #1 : Derivatives

Find the derivative of the function

.

Explanation:

We can use the Chain Rule:

Let , so that .

### Example Question #7 : Specific Derivatives

Compute the derivative of the function .

Explanation:

Use the Chain Rule.

Set  and substitute.