Question

[nguyễn minh]

tìm max:

a, \(A=3\sqrt{2x-1}+x\sqrt{5-4x^2}\) với 1/2<=x<= căn 5/2

b, \(B=\frac{xyz\left(x+y+z+\sqrt{x^2+y^2+z^2}\right)}{\left(x^2+y^2+z^2\right)\left(xy+yz+zx\right)};x,y,z>0\)