Các câu hỏi tương tự
cho a, b>0 va c khac 0. cmr neu 1/a+1/b+1/c=0 thi can(a+b)=can(b+c)+can(c+a)
cho a,b,c khac 0 va a+b+c=0 . tinh Q=\(\frac{1}{a^2+b^2-c^2}+\frac{1}{b^2+c^2-a^2}+\frac{1}{a^2+c^2-b^2}\)
cho (a1)2+...+(a2014)2=2725088015
tinh P=a1+...+a2014, biet a1;...;a2014 la cac so nguyen khac 0
Cac ban oi giai dum minh voi
Cho a,b,c > 0 thoa man abc=1. Chung minh rang 1/(a+1)(b+1) +b/(b+1)(c+1) + c/(c+1)(a+1) >= 3/4
Rut gon da thuc sau: X=\(\sqrt{a^2+1+\left(1-\frac{1}{a+1}\right)^2}+\frac{a}{a+1}\)
voi a>0
Bai1 : Tim max voi x thuoc [1;3]
F(x) = (x-1)(3-x)
G(x)=(2x-1)(3-x)
Bai2: cho a,b>0 thoa man 4/a+1/b=1
Tim min p=a+b
Bai3: cm Voi moi a>0 ta co a^2(1-2a)<=1/27
Bai4: cho a,b,c >0 tm ab+bc+ca=3
Cm a^3+b^3+c^3>=3
Bai5: x,y,z>0 tm xyz=1
Cm x^2\1+y +y^2\1+z + z^2\1+x
cho a,b khac 0 thoa man a+b=1. chung minh \(\frac{a}{b^3-1}+\frac{b}{a^3-1}=\frac{2\left(ab-2\right)}{a^2b^2+3}\)
\(\left(\frac{1}{\sqrt{x}+1}-\frac{1}{x+\sqrt{x}}\right):\frac{\sqrt{x}-1}{x+2\sqrt{x}+1}\) a>0, a khac 1
a)rút gọn Q
b)Tính Q biết x=4
c)tìm x biết Q=1
d)So sánh Q và 1
Cmr voi moi a,b >0 ta co 1/(1+a)^2 + 1/(1+b)^2 = 1/1+ab