The graph of the derivative f ′ of a function f is shown.
The x y-coordinate plane is given. The graph begins on the negative y-axis, goes up and right becoming less steep, passes through the x-axis at x = 1, goes up and right becoming more steep, changes direction sharply above the x-axis at x = 3, goes down and right becoming less steep, passes through the x-axis at x = 4, changes direction below the x-axis at approximately x = 4.5, goes up and right becoming more steep, passes through the x-axis at x = 5, and ends above the x-axis at x = 6.

On what intervals is f increasing? (Enter your answer using interval notation.)

On what intervals is f decreasing? (Enter your answer using interval notation.)

At what values of x does f have a local maximum or local minimum? (Enter your answers as a comma-separated list.)