Giải pt \(\left(\sqrt{x+3}+\sqrt{6-x}\right)\left(6\sqrt{2x+6}-2x-13\right)=6\sqrt{2}\)
giải bất pt
\(\frac{\sqrt{x^2-x-6}+3\sqrt{x}-\sqrt{2\left(x^2+5x+3\right)}}{x+3-\sqrt{2\left(x^2+10\right)}}< =0\)
B1:Giải bpt sau:\(\left(\sqrt{13}-\sqrt{2x^2-2x+5}-\sqrt{2x^2-4x+4}\right).\left(x^6-x^3+x^2-x+1\right)\ge0\)
B2:Cho a;b;c>0 thỏa mãn \(a+b+c=\frac{1}{a}+\frac{1}{b}+\frac{1}{c}\).CMR \(3\left(a+b+c\right)\ge\sqrt{8a^2+1}+\sqrt{8b^2+1}+\sqrt{8c^2+1}\)
B3:giải pt nghiệm nguyên sau : \(6\left(y^2-1\right)+3\left(x^2+y^2z^2\right)+2\left(z^2-9x\right)=0\)
vận dụng bđt để giải Pt sau
\(\sqrt{2x-1}+\sqrt{19-2x}=\frac{6}{-x^2+10x-24}\)\(\left|x+1\right|+\left|x+2\right|+...+\left|x+2005\right|=2006x\)x2=2x8+\(\frac{3}{8}\)\(x+\sqrt{3+\sqrt{x}}=3\)\(8x^2+\sqrt{\frac{1}{x}}=\frac{5}{2}\)giải pt
\(\frac{2\left(x-\sqrt{2}\right)\left(x-\sqrt{3}\right)}{\left(1-\sqrt{2}\right)\left(1-\sqrt{3}\right)}+\frac{3\left(x-1\right)\left(x-\sqrt{3}\right)}{\left(\sqrt{2}-1\right)\left(\sqrt{2}-\sqrt{3}\right)}+\frac{4\left(x-1\right)\left(x-\sqrt{2}\right)}{\left(\sqrt{3}-1\right)\left(\sqrt{3}-2\right)}\)=3x-1
giải pt
\(\left(2x+1\right)\sqrt{\frac{x+1}{x}}=x+2+\sqrt[3]{2x^2+x^3}\)
giải pt bằng cách đặt ẩn phụ:
a) \(x^3+\sqrt{\left(1-x^2\right)^3}=x\sqrt{\left(2-2x^2\right)}\)
b) \(\frac{9-2x}{\sqrt{\left(4-x\right)}}+\frac{4x+3}{\sqrt{\left(4x+1\right)}}=\frac{15}{2}\)
c) \(\sqrt[3]{\left(7-16x\right)}+2\sqrt{\left(2x+8\right)}=5\)
d) \(5\sqrt{\left(x+1\right)}-2\sqrt[3]{\left(7x+6\right)}=4\)
1)giải pt \(x^3-9x^2+6x-6-3\sqrt[3]{6x^2+2}=0\)
2) giải hệ pt \(\int^{\sqrt{x}\left(1+\frac{3}{x+3y}\right)=2}_{\sqrt{7y}\left(1-\frac{3}{x+3y}\right)=4\sqrt{2}}\)
+Tuấn 10B_2 (T ko biết đánh word nên dùng tạm .V)
GPT: \(\(\sqrt{x+3}+\sqrt[3]{x}=3\)\) (Bài này cách lp 9 dễ t ko giải nữa)
Vì \(\(f\left(x\right)=\sqrt{x+3}+\sqrt[3]{x}=3\)\) là hàm tăng trên tập [-3;\(\(+\infty\)\))
Ta có: Nếu \(\(x>1\Leftrightarrow f\left(x\right)>f\left(1\right)=3\)\)nên pt vô nghiệm
Nếu \(\(-3\le x< 1\Leftrightarrow f\left(x\right)< f\left(1\right)=3\)\)nên pt vô nghuêmj
Vậy x = 1
B2, GHPT: \(\(\hept{\begin{cases}2x^2+3=\left(4x^2-2yx^2\right)\sqrt{3-2y}+\frac{4x^2+1}{x}\\\sqrt{2-\sqrt{3-2y}}=\frac{\sqrt[3]{2x^2+x^3}+x+2}{2x+1}\end{cases}}\)\)
ĐK \(\(\hept{\begin{cases}-\frac{1}{2}\le y\le\frac{3}{2}\\x\ne0\\x\ne-\frac{1}{2}\end{cases}}\)\)
Xét pt (1) \(\(\Leftrightarrow2x^2+3-4x-\frac{1}{x}=x^2\left(4-2y\right)\sqrt{3-2y}\)\)
\(\(\Leftrightarrow-\frac{1}{x^3}+\frac{3}{x^2}-\frac{4}{x}+2=\left(4-2y\right)\sqrt{3-2y}\)\)
\(\(\Leftrightarrow\left(-\frac{1}{x}+1\right)^3+\left(-\frac{1}{x}+1\right)=\left(\sqrt{3-2y}\right)^3+\sqrt{3-2y}\)\)
Xét hàm số \(\(f\left(t\right)=t^3+t\)\)trên R có \(\(f'\left(t\right)=3t^2+1>0\forall t\in R\)\)
Suy ra f(t) đồng biến trên R . Nên \(\(f\left(-\frac{1}{x}+1\right)=f\left(\sqrt{3-2y}\right)\Leftrightarrow-\frac{1}{x}+1=\sqrt{3-2y}\)\)
Thay vào (2) \(\(\sqrt{2-\left(1-\frac{1}{x}\right)}=\frac{\sqrt[3]{2x^2+x^3}+x+2}{2x+1}\)\)
\(\(\Leftrightarrow\sqrt{\frac{1}{x}+1}=\frac{\sqrt[3]{x^2\left(x+2\right)}+x+2}{2x+1}\)\)
\(\(\Leftrightarrow\left(2x+1\right)\sqrt{\frac{1}{x}+1}=x+2+\sqrt[3]{x^2\left(x+2\right)}\)\)
\(\(\Leftrightarrow\left(2+\frac{1}{x}\right)\sqrt{1+\frac{1}{x}}=1+\frac{2}{x}+\sqrt[3]{1+\frac{2}{x}}\)\)
\(\(\Leftrightarrow f\left(\sqrt{1+\frac{1}{x}}\right)=f\left(\sqrt[3]{1+\frac{2}{x}}\right)\)\)
\(\(\Leftrightarrow\sqrt{1+\frac{1}{x}}=\sqrt[3]{1+\frac{2}{x}}\)\)
\(\(\Leftrightarrow\left(1+\frac{1}{x}\right)^3=\left(1+\frac{2}{x}\right)^2\)\)
Đặt \(\(\frac{1}{x}=a\)\)
\(\(\Rightarrow Pt:\left(a+1\right)^3=\left(2a+1\right)^2\)\)
Tự làm nốt , mai ra lớp t giảng lại cho ...