①1-x≥0,且x≥0,所以0≤x≤1,即定义域为[0,1]令x=(sint)^2 (0≤t≤π/2),那么y=√[1-(sint)^2]-√(sint)^2=cost-sint=√2*cos(t+π/4)因为0≤t≤π/2,所以π/4≤t+π/4≤3π/4,所以-√2/2≤cos(t+π/4)≤√2/2,所以...