chung minh neu a,b,c=(0;1) thi co it nhat mot trong cac bat dang thuc sau day dung:a(1-b) <1/4 ; b(1-c)<1/4 ; c(1-a)<1/4
chung minh neu a,b,c=(0;1) thi co it nhat mot trong cac bat dang thuc sau day dung:a(1-b) <1/4 ; b(1-c)<1/4 ; c(1-a)<1/4
Bai 1)Cho bieu thuc A=\(\frac{x+y-2\sqrt{xy}}{x-y}\)
a)Tim dieu kien de A co nghia
b)Rut gon A
c)Tinh A biet x=\(3+2\sqrt{2}\)va y=\(3-2\sqrt{2}\)
Bai 2) Cho bieu thuc B=\(\frac{x-3}{\sqrt{x-1}-\sqrt{2}}\)
a)Tim dieu kien de B co nghia
b)Rut gon B
c) Tinh B voi x=\(4\left(2-\sqrt{3}\right)\)
d)Tim x de B co gia tri nho nhat
Cho a,b,c la cac so thuc t/m (a+2)(b+2)=25/4
Tim gia tri nho nhat cua \(F=\sqrt{1+a^4}+\sqrt{1+b^4}\)
voi a,b,c,d la cac so duong thoa man a*b = c*d = 1. Chung minh bat dang thuc ( a+b )*( c+d ) + 4 >= 2( a+b+c+d )
chung minh bat dang thuc 2(a^4+1) + (b^2 +1)^2>=2(ab+1)^2
Cho pt 2x^2 +2mx +m^2-2
a. Tim m de pt co ngo
b. Tim GTLN cua bieu thuc C=|2x1x2+x1+x2-4|
voi a,b,c,d, la cac so duong thoa man a*b = c*d =1 chung minh bat dang thuc : ( a+b )*( c+d ) +4 >= 2*( a+b+c+d ) cac ban oi giup minh voi OK
cho he phuong trinh mx-y=m2 va 2x + my= m2 + 2m + 2
a, chung minh rang he phuonh trinh luon co 2 nghiem duy nhat voi moi m
b, tim m de bieu thuc: A = x2 + 3y + 4 nhan gia tri nho nhat
c, khi he co nghien duy nhat (x;y) chung minh M (x;y) luon nam tren duong thang co dinh