tim so tu nhien co bon chu so .Biet so do la mot so chinh phuong va neu them vao moi chu so 1 don vi thi ta cung duoc mot so chinh phuong

cho a,b,c,d la cac so thuc thoa ma dang thuc a+b+c+d=0.chung minh rang:

\(a^3+b^3+c^3+d^3=3\left(b+d\right)\left(ac-bd\right)\)

giai phuong trinh :

\(\dfrac{\sqrt{x+3}+\sqrt{x-1}}{\sqrt{x+3}-\sqrt{x-1}}=\dfrac{13-x^2}{4}\)

tim tat ca cac nghiem nguyen cua phuong trinh :

\(x^2y^2-2x\left(y+2\right)+4=0\)

cho so tu nhien n \(\ge\) 1.chung minh rang :

\(2^n.n!\le\left(n+1\right)^n\le\left(2n\right)^n\)

thuyet minh but bi

thuyet minh ao dai Viet Nam

giai phuong trinh \(x^2-5x+4=2\sqrt{2x-4}\)

tim gia tri lon nhat cua bieu thuc \(f\left(x\right)=\dfrac{1}{x^4-x^2+1}\)

cho \(\Delta\) ABC co cac canh a,b,c va chu vi 2p=a+b+c

chung minh \(\dfrac{1}{p-a}+\dfrac{1}{p-b}+\dfrac{1}{p-c}\ge2\left(\dfrac{1}{a}+\dfrac{1}{b}+\dfrac{1}{c}\right)\)