Find the intervals where the function is increasing or decreasing. 1 1 4 f x = x2 x ) ( ) 4 2 Find all critical numbers of the function. Then use the first-derivative test to find all numbers at which the function has a relative maximum or minimum on the interval (3, 5). 5) f(x) = x3 12x +4 Use the second-derivative test to find all numbers at w hich the function has a relative maximum or minimum. 6 = X we A4