Cho a,b là các số thực thỏa mãn a2+b2-ab=4.CMR \(\dfrac{8}{3}\le a^2+b^2\le8\)
Let a,b be real nmubers.Prove that \(P=a^2+b^2-a-b-ab\ge-1\)
Luân ĐàoGiven a set three integers greater than 1.
Let A be the number that's 1 less than the product of three given integers.
Let B be the product of numbers that're 1 less than three given integers.
Known that A is a multiple of B.
How many sets can you find.
A. 1
B. 2
C. 3
D. 4
Chứng minh đẳng thức:
a) \(\dfrac{a}{b}\) + \(\dfrac{b}{a}\) ≥ 2 (a,b > 0)
b) 2(a2 + b2) ≥ (a + b)2
Let N be the langest number ò region that can be formed by drawing 2016 straight lines on a plane. Find the sum ò all digits of N.
Cho a+b+c=0 ; \(\dfrac{1}{a}\)+\(\dfrac{1}{b}\)+\(\dfrac{1}{c}\)=0. Chứng minh rằng: a2+b2+c2=1
Toán tiếng anh: Let a, b, c be the possible integer such that ab+bc=518 and ab-ac=360. Find the largest possible value of the product abc
Chứng minh các bất đẳng thức:
a) \(\dfrac{a^2+a+1}{a^2-a+1}\) > 0
b) a2 + b2 + c2 + 3 ≥ 2(a + b + c)
Chứng minh các bất đẳng thức:
a) (\(\dfrac{a+b}{2}\))2 ≥ \(\dfrac{a^2+b^2}{2}\)
b) (a10 + b10)(a2 + b2) ≥ (a8 + b8)(a4 + b4)