ĐKXĐ: ...
\(A=-\left(2-x\right)+\sqrt{2-x}-\frac{1}{4}+\frac{9}{4}\)
\(A=-\left(2-x-\sqrt{2-x}+\frac{1}{4}\right)+\frac{9}{4}\)
\(A=-\left(\sqrt{2-x}-\frac{1}{2}\right)^2+\frac{9}{4}\le\frac{9}{4}\)
\(A_{max}=\frac{9}{4}\) khi \(\sqrt{2-x}=\frac{1}{2}\Rightarrow x=\frac{7}{4}\)
Tim GTNN, GTLN cua:
\(A=\left|x-\sqrt{2}\right|+\left|y-1\right|\) voi \(\left|x\right|+\left|y\right|=5\)
Tim GTLN,GTNN cua A\(=\dfrac{x+1}{x^2+x+1}\)
can gap juup vs
P = \(\frac{2\sqrt{x}-9}{\left(\sqrt{x}-3\right)}+\frac{2\sqrt{x}+1}{\sqrt{x}-3}-\frac{\sqrt{x}+3}{\sqrt{x}-2}\) a) Tim dieu kien xac dinh cua P
cho a,b,c>0 thoa man a+b+c=3. Tim GTLN cua P=\(a\sqrt{b}+b\sqrt{c}+c\sqrt{a}-\sqrt{abc}\)
Cho \(A=\dfrac{\sqrt{x-1-2\sqrt{x-2}}}{\sqrt{x-1}-1}\)
a/Tim DKXD cua A
b/Rut gon A
1) Cho bieu thuc: \(B=\left(\frac{\sqrt{x}}{\sqrt{x}+4}+\frac{4}{\sqrt{x}-4}\right):\frac{x+16}{\sqrt{x}+2}\left(x\ge0,x\ne16\right)\)
a) Cho bieu thuc A= \(\frac{\sqrt{x}+4}{\sqrt{x}+2}\) ; voi cac cua bieu thuc A va B da cho, hay tim cac gia tri cua x nguyen de gia tri cua bieu thuc B(A;-1) la so nguyen
tìm gtln cua \(C=x+\sqrt{2-x}\)
Cho P = \(\left(\dfrac{1}{\sqrt{x}+1}-\dfrac{2\sqrt{x}-2}{x\sqrt{x}-\sqrt{x}+x-1}\right)\): \(\left(\dfrac{1}{\sqrt{x}-1}+\dfrac{2}{x-1}\right)\)
a/ Tim DKXD va rut gon P
b/ Tim cac gia tri nguyen cua x de P co gia tri nguyen
1) Cho bieu thuc \(A=\frac{x}{x-4}+\frac{1}{\sqrt{x}-2}+\frac{1}{\sqrt{x}+2}\)
a) Tim tat ca cac gia tri cua x de A>1
