Question

Answer 1

lỗi

Answer 2

lx

Answer 3

it's not your fault she did it on purpose

Answer 4

Phương trình có nghiệm khi:

\(\Delta=m^2-4020m\ge0\Rightarrow\left[{}\begin{matrix}m\le0\\m\ge4020\end{matrix}\right.\)

Theo hệ thức Viet: \(\left\{{}\begin{matrix}x_1+x_2=m\\x_1x_2=1005m\end{matrix}\right.\)

\(M=\dfrac{2x_1x_2+2680}{\left(x_1+x_2\right)^2+1}=\dfrac{2010m+2680}{m^2+1}=\dfrac{-335\left(m^2+1\right)+335m^2+2010m+3015}{m^2+1}\)

\(M=-335+\dfrac{335\left(m+3\right)^2}{m^2+1}\ge-335\)

\(M_{min}=-335\) khi \(m+3=0\Rightarrow m=-3\)