\(x=\left\{1,2\right\}\) là nghiệm \(\Rightarrow\left\{{}\begin{matrix}f\left(1\right)=0\\f\left(2\right)=0\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}1^2+b.1+c=0\\2^2+b.2+c=0\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}b+c+1=0\\2b+c+4=0\end{matrix}\right.\)\(\Rightarrow\left\{{}\begin{matrix}b=-3\\c=2\end{matrix}\right.\)
1)Tim he so a cua da thuc A(x)=-7x2-3y2 +9xy-2x2+y2,biet rang da thuc co1 nghiem bang\(\dfrac{1}{2}\)
2) Tim m, biet rang da thuc Q(x)=mx2 + 2mx -3co 1 nghiemx=-1
Chung to da thuc M(x)=(x-3)2 + |2-x| vo nghiem
THONG CAM NHA TAI VI MAY MINH HK CAI BAN PHIM TIENG VIET . GIUP MK NHA CAC BAN. MAI MK KIEM TRA RUI
Chung to rang neu a+b+c=0 thi x=1 la mot nghiem cua da thuc ax\(^2\)+bx+c.
tim nghiem da thuc 4x+9 , -5x+6 , x^2-1 , x^2-9 , x^2-x , x^2-2x , x^2-3x , 3x^2-4x
bai 1
xac dinh he so a, b biet da thuc A(x) = ax2+bx+2 co bac 1 va A(1)=4
cmr da thuc sau khong co nghiem : \(x^{10}-x^5+x^2-x+1\)
x2-12x+20
tim nghiem da thuc
Cho hàm số : y = f (x) = ax2 + bx + c
Biet : f (0) = 2010 ; f (1) = 2011 ; f (-1) = 2012
Tinh f (-2) ?
1. cho da thuc f(x)= x5 -2001 x4 +2001 x3-2001x2 2001 x-1.tính (f )=2000.
2.cho da thuc M=2x-x2+3 [x+1]
a. thu gon da thuc tren
b.tinh m khi x = -3 phan 2
