Bài 8: Rút gọn biểu thức chứa căn bậc hai
Các câu hỏi tương tự
Cho A = \(\left(\dfrac{\sqrt{x}+\sqrt{y}}{1-\sqrt{xy}}+\dfrac{\sqrt{x}-\sqrt{y}}{1+\sqrt{xy}}\right):\left(1+\dfrac{x+y+2xy}{1-xy}\right)\)
a, Rut gon bieu thuc A
b, Tinh gia tri cua A khi x = \(\dfrac{1}{1+\sqrt{2}}\)
c, Tim Max A
A=(\(\frac{1}{\sqrt{x}-1}\)+\(\frac{1}{\sqrt{x}+1}\))2.\(\frac{x^2-1}{2}\)-\(\sqrt{1-x^2}\)
1)tim dk cua x de bieu thuc A co nghia
2)rut gon bieu thuc A
3) giai phuong trinh theo x khi A=-2
rut gon bieu thuc 2x2\(\sqrt{\frac{9}{x^4}}\) voi x<0
B=\(\left(\frac{1}{x+\sqrt{x}}+\frac{1}{\sqrt{x}+1}-1\right):\frac{\sqrt{x}-1}{\sqrt{x}-2}\)
a,Rut gon B
b,Tim cac gia tri cua x de 3B=\(2\sqrt{x}-7\)
Bai tap: Cho:
\(A=\left(\dfrac{1}{x+\sqrt{x}}+\dfrac{1}{\sqrt{x}+1}\right):\dfrac{\sqrt{x}-1}{x+2\sqrt{x}+1}+1\)
a) Rut gon
b) Tinh gia tri cua A voi \(x=1\dfrac{1}{3}\)
M=\(\dfrac{x\sqrt{x}-1}{x-\sqrt{x}}-\dfrac{x\sqrt{x}+1}{x+\sqrt{x}}+\dfrac{x+1}{\sqrt{x}}\)với x>0,\(x\ne1\)
Rut gon bieu thuc M
Tìm x để M=\(\dfrac{9}{2}\)
So sanh M va 4
tim gia tri nho nhat cua B=(\(\sqrt{x}\)-2)/(\(\sqrt{x}\)+1)
tim gia tri nho nhat cua A=(x - 5\(\sqrt{x}\)+6)/(x + 7\(\sqrt{x}\)+6)
Rut gon bieu thuc : \(\frac{2xy^2}{3ab}\sqrt{\frac{9a^3b^4}{8xy^3}}\)