Bằng nhau nha bạn
x\(^2\)> 2x\(\forall\)x
Bạn Việt Anh sai rồi
TH1:x<2
Suy ra x^2>2x(Vì x^2>=0 còn 2x<0)
TH2:x=2 thì x^2=2x
TH3:x>2
Suy ra x.x>2.x
Suy ra x^2>2x
Các câu hỏi tương tự
Tim 3 so nguyen to lien tiep x, y, z ( voi x < y < z ) sao cho so A=\(x^2\)+\(y^2\)+\(z^2\)la mot so nguyen to.
chung-to-rang-a-n9999n2014-la-mot-so-chan-voi-moi-so-nguyen-n.
giup toi giai bai nay voi:
cho 3 so nguyen a,b,0 biet a la mot so nguyen am va a<b .sap xep ba so do tang dan
cho 26 so nguyen,trong do tong cua 5 so bat ki la mot so nguyen duong.chung to rang tong cua 26 so nguyen da ch la mot so nguyen duong.
Cho 1 so nguyen a khac 0. So sanh -a voi a,-a voi 0
dien dung sai
a/tich cua hai so nguyen duong la mot so nguyen duong
b/tich cua hai so nguyen am la mot so nguyen am
c/tich cua 2 so nguyen cung dau luon lon hon moi so do
d/tich cua hai so nguyen khac dau luon nho hon moi so do
e/neu tich hai so nguyen la mot so nguyen duong thi hai so do deu la so nguyen duong
f/neu tich hai so nguyen la mot so nguyen am thi hai so do deu la so nguyen am
tim so nguyen duong nho nhat de khi nhan no voi moi mot trong cac phan so toi gian 3/4, -5/11, 7/12 deu duoc tich la nhung so nguyen
tim so nguyen duong nho nhat de khi nhan no voi moi mot trong cac phan so toi gian 3/4;-5/11;7/12 deu duoc ket qua la nhung so nguyen
a,tim so nguyen x sao cho x+2/x-5 la so nguyen duong
b,so sanh
A=20mu10+1/20mu10-1va B=20mu10-1/20mu10-3