Part 2: Paper6 (Science) and Paper 5(social science)

 $P\left(x\right)=ax+b\ ,\ a,b\in R\ ,\ a\ne0$  

 $P\left(x\right)=ax^2+bx+c\ ,\ a\ne0\ ,\ a,b,c\in R$  

 $P\left(x\right)=k\left(ax^2+bx+c\right)\ ,\ a,b,c,k\in R$  

 $P\left(x\right)=A\left(x\right)e^{\alpha x}\ ,\ A\in R$  

 $y=Ae^{-a\ x}\ \ ,\ A\in R$  

 $y=Ae^{ax}\ ,\ A\in R$  

 $y=-Ae^{ax}\ ,\ A\in R$  

 $y=-Ae^{-ax}\ ,\ A\in R$  

 $\overrightarrow{AB}\times\overrightarrow{AC}=\left(yz\ '\ -y\ 'z\right)\overrightarrow{i\ \ }-\left(xz\ '\ -x\ '\ z\right)\overrightarrow{j\ \ }+\left(xy\ '\ -x\ '\ y\ \right)\overrightarrow{k\ \ }$  

 $\overrightarrow{AB}\times\overrightarrow{AC}=xx\ '\ +y\ y\ '\ +z\ z\ '$  

 $\overrightarrow{AB}\times\overrightarrow{AC}=\left(yz\ '\ -y\ 'z\right)\overrightarrow{i\ \ }+\left(xz\ '\ -x\ '\ z\right)\overrightarrow{j\ \ }+\left(xy\ '\ -x\ '\ y\ \right)\overrightarrow{k\ \ }$  

 $\overrightarrow{AB}\times\overrightarrow{AC}=\left|\overrightarrow{AB}\right|\cdot\left|\overrightarrow{AC}\right|\cdot\cos\alpha$