k=dy/dx
dy=y(b)-y(a)=1-(-3)=4
dx=x(b)-x(a)=2-0=2
k=4/2=2
y=2x+L
take point B (or A as u like)
1=2+2+L
L=-3
k=dy/dx
dy=y(b)-y(a)=1-(-3)=4
dx=x(b)-x(a)=2-0=2
k=4/2=2
y=2x+L
take point B (or A as u like)
1=2+2+L
L=-3