# How do you find local maximum value of f using the first and second derivative tests: #f(x)= sinx#?

##### 1 Answer

#### Answer:

The max occurs at

#### Explanation:

#cos x=0# at#x= pi/2, (3pi)/2, "etc."#

Make a sign chart for

At the critical point where

#-sin(pi/2) = -1 <0#

Since the second derivative is negative at