(1+\(\sqrt{2}+\sqrt{3}\))(\(1+\sqrt{2}-\sqrt{3}\))

a)\(\sqrt{12}+\dfrac{4}{\sqrt{3}-\sqrt{5}}\)

b) \(\dfrac{\sqrt{45}}{\sqrt{6}-2}-\sqrt{20}\)

1,

A=\(3\sqrt{8}-\sqrt{50}-\sqrt{\sqrt{2}-1}\)

B=2\(\dfrac{2}{x-1}\sqrt{\dfrac{x^2-2x+1}{4x^2}}\) với 0<x<1

2,Giải pt

\(\sqrt{x^2-3x+2}+\sqrt{x+2}=\sqrt{x+2}+\sqrt{x^2+2x+3}\)

Tìm x

a)\(\sqrt{x^2-1}\) -\(x^2\)+1=0

b)\(\sqrt{x+2\sqrt{x-1}}\) + \(\sqrt{x-2\sqrt{x-1}}\)

c) \(\sqrt{3x^2+12x+16}\) + \(\sqrt{4x^2+6x+25}\)=1-\(x^2\)-4x

2.Rút gọn

a)\(\sqrt{\left(1-\sqrt{2}\right)^2}\) + \(\sqrt{\left(\sqrt{2}-3\right)^2}\)

b) \(\sqrt{4-2\sqrt{3}}\) + \(\sqrt{7}\) - \(\sqrt{48}\)

c) \(\sqrt{3-\sqrt{8}}\) (3+\(\sqrt{5}\)) ( \(\sqrt{16-\sqrt{2}}\))

Tìm điểm cực đại của đồ thị hàm số   y = x 4 − 2 x 2 + 2

A. − 1 ; 1

B. 2 ; 0

C. 1 ; 1

D. 0 ; 2