1) Chung minh tong hai so nguyen to la mot hop so
VD: 3+5=8
2) Phan tich da thuc 4x2-a2+y2-16b2+4xy+8ab thanh nhan tu
3) Gia tri nho nhat cua bieu thuc M= (x-1)(x+5)(x2+4x+5) la ...
1) Phan tich da thuc sau thanh nhan tu: x2-x-2008.2009
2) Chung minh rang voi moi x,y,z ta luon co: x2+4y2+z2>=2x+12y+4z
3) Cho a-b=4. Tinh gia tri cua bieu thuc: a3-12ab-b3
cac ban lam duoc cau nao thi giup mik nha. mik dang can gap lam
chung minh rang a,b,c la do dai 3 canh cua mot tam giac thi m=4a2b2-(a2+b2-c2)2 luon duong
cho hinh thang ABCD(AB//CD)
a)chung minh rang neu hai tia phan giac cua hai goc A va D cung di qua trung diem F cua canh ben BC thi canh ben AD bang tong hai canh day
b) chung minh rang neu AD=AB+CD thi tia phan giac cua hai goc A va B cat nhau tai trung diem cua canh ben BC
Cho a, b, c la do dai ba canh cua mot tam giac . Chung minh rang :
\(\frac{1}{a+b-c}+\frac{1}{a+c-b}+\frac{1}{b+c-a}\ge\frac{1}{a+b+c}\)
Viet bieu thuc sau duoi dang binh phuong cua mot tong:
2xy2 +x2y4 +1
Phan tich da thuc sau thanh nhan tu:
a) x2 -3x +2
b) 3x2 - 7x -10
c) 2x2 -5x -7
HELP ME!!!
phan tich da thuc sau thanh nhan tu
xy(x+y) + yz(y+z) + xz(x+z) + 2xyz
tinh gia tri bieu thuc
3(x-3)(x+7) + (x-4)2 + 48 tai x = 0,5
chung minh rang
x2 - 6x + 10 >0 voi moi x
4x - x2 - 5 <0 voi moi x
chung minh rang ba trung tuyen cua mot tam giac chia tam giac do thanh 6 phan co dien tich bang nhau
1.cho phan thuc P=\(\frac{5x-4y}{5x+4y}\)voi 25x2+16y2=50xy.khi do gia tri cua bieu thuc P=\(\frac{1+P^2}{1-P^2}\)la
2.gia tri lon nhat cua bieu thuc B=\(\frac{14}{\frac{x^2}{4}-3x+16}la\)
3.gia tri cua a de da thuc A=2x3+7x2+ax+3 chia het cho B=(x+1)2la a=?