1.ta có: 7x-2x^2=-2(x^2-7/2x)
=-2(x^2-2*7/4x+49/16-49/16)
=-2(x-7/4)^2+49/8 <=49/8
Dấu bằng xáy ra <=> x=7/4
Vậy max=49/8 <=> x=7/4
1. nghiem nho nhat cua da thuc 11x-2x2-15
2.gia tri x nho nhat thoa man : 4x2+7x+3=0
3.gia tri lon nhat cua bieu thuc7x-2x2
.
1. tich cac gia tri x thoa man x2-\(\frac{1}{10}\)x-\(\frac{1}{5}\)+0
2.gia tri cua x de bieu thuc A=6x2+7x-8 dat gia tri nho nhat
3.tích cac gia tri cua x thoa man (2x-1)2=(2-x)2
1. gia tri cua x thoa man (2x+3)(x+1)2-(2x+3)(2x-3)
2. so nghiem cua da thuc x3+6x2+11x+6 la ?
3. bieu thuc C = 8-5x-2x2 dat gia tri lon nhat tai x = ?
1.nghiem nho nhat cua da thuc : 11x-2x2-15
2.gia tri x nho nhat thoa man 4x2+7x+3=0
3.gia tri cua x3+y3biet x+y=2 va x2+y2=20
tim gia tri nho nhat cua bieu thuc tim gia tri nho nhat cua bieu thuc x^4-4x^3+12x^2-16x+16
giup to 3 bai nay
1. gia tri cua x thoa man (2x+3)(x+1)2-(2x+3)(2x-3)
2. so nghiem cua da thuc x3+6x2+11x+6 la ?
3. bieu thuc C = 8-5x-2x2 dat gia tri lon nhat tai x = ?
giup to 3 bai nay
1. gia tri cua x thoa man (2x+3)(x+1)2-(2x+3)(2x-3)
2. so nghiem cua da thuc x3+6x2+11x+6 la ?
3. bieu thuc C = 8-5x-2x2 dat gia tri lon nhat tai x = ?
cho x,y,z la cac so thuc duong thoa man x+y+z=1 tim gia tri nho nhat cua bieu thuc M=1/16x+1/4y+1/z
Tim gia tri cua x de bieu thuc P=(x^2-2x+1989)/x^2 dat gia tri nho nhat.
