Gợi ý thôi.
\(x^3-ax^2+bx-c=\left(x-a\right)\left(x-b\right)\left(x-c\right)\)
\(\Rightarrow x^3-ax^2+bx-c\)có ba nghiệm \(x=a,x=b,x=c\)
Theo định lí Vi-et:\(\hept{\begin{cases}a+b+c=a\\ab+bc+ca=b\\abc=c\end{cases}\Leftrightarrow}\hept{\begin{cases}b=-c\\ab+bc+ca=b\\c\left(ab-1\right)=0\end{cases}}\)
okeee cam on ban
Dang I: tinh gia tri bieu thuc
Bai 12: Cho x=2011. tinh gia tri chua bieu thuc
\(x^{2011}-2012x^{2010}+2012x^{2009}-2012x^{2008}+....-2012x^2+2012x-1\)
bai 11: Cho da thuc P(x)=ax\(^3\)+bx\(^2\)+cx+d (a khac 0)
Biet p(1)=100, p(-1)=50,p(0)=1,[(1)=120. Tinh p(3)
bai 10: Tam thuc bac hai la da thuc co dang f(x) =ax+b voi a,b,c la hang a khac 0. Hay xac dinh cac he so a,b biet f(1)=2 , F(3)=8
cho 2 bieu thuc A=x+x^2/2-x va B=2x/x+1+3/x-2-2x^2+1/x^2-x-2 a, tinh gia tri cua A khi /2x-3/=1 b,tim dieu kien xac dinh va rut gon bieu thuc B c,tim so nguyen x de P=A.B dat gia tri lon nhat
mk dang can gap
bai 1
a = (3x / 2x + 4 ) + (x +3 /x ^ 2 - 4 )
a . tim x de gia tri phan thuc a duoc xac dinh
b. rut gon a
c. tinh gia trin cua a khi x bang -3
d . tim gia tri cua x de phan thuc co gia tri bang 2
1.Xac dinh a,b,c
a, x^3+3x^2-x-3=(x-2).(x^2+bx+c)+a
b,4x^3+7x^2+7x-6=(ax+b).(x^2+x+1)+c
giup minh voi nha.
xac dinh a , b,c sao cho 2x^4 + ax^2 +bx +c chia het cho (x-2) va chia (x^2-1) du 2x
cho phan thuc 4x-4/2x^2-2 :
a) Tim dieu kiem xac dinh
b)cho gia tri cua x=-2 tinh phan thuc
c) Tim gia tri cua x de gia tri phan thuc la so nguyen
cho bt \(A=\frac{x^2}{x^2-4}-\frac{x}{x+2}-\frac{2}{x-2}\)
a, tim x de ieu thuc A duoc xac dinh
b,rut gon bieu thuc A
c,tim gia tri nguyen cua x de A nguỵen
xac dinh cac he so a va b
x4 + ax2 + b chia het cho x2 - x +1
ax3 + bx2 + 5x chia het cho x2 + 3x - 10
ax4 + bx3 + 1 chia het cho (x - 1)2
x4 - 4 chia het cho x2 + ax +b
phân tích cac da thuc sau thanh nhan tu:
a) x^3-2x^2 +2x -13
b) x^2y+xy +x +1
c) ax+by+ay+bx
d) x^2 -(a+b)x +ab
e) x^2y +xy^2 -x-y
f) ax^2 +ay-bx^2-by
