# Derivative of Tangent Function (Investigation)

- Author:
- Tim Brzezinski

Displayed below is the graph of .
The

**y-coordinate of the****blue point****= the slope of the line tangent to the graph of**BIG WHITE POINT. Drag this BIG WHITE POINT around to*f*at the**observe the graph of the derivative**of function*f*being traced out. Without opening up another tab in your browser to look it up, feel free to take a guess as to what the derivative of this function might be. (You don't have to do this right away, but you will eventually in the questions that follow.)## 1)

Recall the trigonometric identities you've learned previously. Is there a special relationship between the tangent, sine, and cosine of an angle?

## 2)

Determine the derivative of the function by applying the quotient rule to the expression you obtained in (1) above.

## 3)

Rewrite the expression you obtained in (2) so that it's not written as a quotient.