a) stim ca functia arcsin este definita pe [-1,1]
deci -1≤ x patrat -1≤1
0≤x patrat≤2
0≤x≤rad 2
si x≥0
deci D=[0,rad2]
b) f(0)+f(1)= arcsin(o patrat-1)+ arccos(rad 0) + arcsin (1 la patrat -1) + arccos (rad1)= arcsin(-1)+arccos(0) + arcsin(0) + arccos(1)= -phi/2+ phi/2 +0+0=0
