F ( x ) = 4 + 2 x 2 − x 4 (a) Find the interval(s) of increase. (Enter your answer using interval notation.) (-oo,-1)U(0,1) ( − [infinity] , − 1 ) ∪ ( 0 , 1 ) . Find the interval(s) of decrease. (Enter your answer using interval notation.) (-1,0)U(1,oo) ( − 1 , 0 ) ∪ ( 1 , [infinity] ) . (b) Find the local minimum value(s). (Enter your answers as a comma-separated list. If an answer does not exist, enter DNE.) Find the local maximum value(s). (Enter your answers as a comma-separated list. If an answer does not exist, enter DNE.)