1. Derivatives of Trig Functions
London Bridge, Lake Havasu City, Arizona

2. Consider the function
slope
We could make a graph of the slope:
Now we connect the dots!
The resulting curve is a cosine curve.

3. We can do the same thing for
slope
The resulting curve is a sine curve that has been reflected about the x-axis.

4. We can find the derivative of tangent x by using the quotient rule.

5. Derivatives of the remaining trig functions can be determined the same way.p

6. Proof that derivative of sin(x)= cos(x)
Using the definition of the derivative
Formulas needed in proof
sin (a+b) = sin a cos b + cos a sin b