2a√[(1+b^2)/2]<=a^2+(1+b^2)/2=a^2+b^2/2+1/2=1+1/2=3/2所以(2/√2)*a√(1+b^2)<=3/2a√(1+b^2)<=3√2/4当a^2=(1+b^2)/2时取等号代入a^2+b^2/2=11/2+b^2=1b^2=1/2,a^2=3/4,所以等号能取到所以a√(1+b^2)最大值=3√2/4
a^2+b^2/2=1a^2+(1+b^2)/2=3/2≥2a√[1+(b^2)]a√[1+(b^2)]≤3/4