fff
To find increasing and decreasing intervals we take derivative
Now we set the derivative =0 and solve for x
sinx + cosx =0
divide whole equation by cos x
tanx +1 =0
tanx = 1
and
Now we pick a number between 0 to
Lets pick
Plug it into the derivative
= 4.810 is positive
So the graph of f(x) is increasing on the interval [0, )
Now we pick a number between to 2pi
Lets pick
Plug it into the derivative
= 116 is positive
So the graph of f(x) is increasing on the interval
Increasing interval is
Decreasing interval is
(b)
The graph of f(x) increases and reaches a local maximum at
The graph of f(x) decreases and reaches a local minimum at
(c)
f(0) = 0
Here global maximum at
Here global minimum at