(1)配方,求出函数顶点式f(x)=x^2-x=(x^2-x+1/4)-1/4=(x-1/2)^2-1/4∴当-1≤x≤4时可知当x=1/2时(即顶点),f(x)最小当x=4时,f(x)最大f(x)min=f(1/2)=-1/4f(x)max=f(4)=12∴值域为[-1/4,12](2)换元法令a=1+x,则x=a-1 ∵...