Hello,
This is my first post and I'll keep visit here to ask or answer if I know
I'm reading a book and I don't understand how this works.
x = Px + tdx
y = Py + tdy
and
\(\displaystyle y = dy\tfrac{x-Px}{dx} + Py\)
and it become a
\(\displaystyle 0 = \tfrac{y-Py}{dy} - \tfrac{x-Px}{dx}\)
and then it become a
= (-dy)x + (dx)y + (dyPx - dxPy)
= ax + by + c
I really don't understand is that how I can get
(-dy)x + (dx)y + (dyPx - dxPy)
from
\(\displaystyle 0 = \tfrac{y-Py}{dy} - \tfrac{x-Px}{dx}\)
I always get this
\(\displaystyle \frac{(y-Py)dx - (x-Px)dy}{dydx}\)
I don't know how to get rid of dydx in the bottom.
Thanks for help
This is my first post and I'll keep visit here to ask or answer if I know
I'm reading a book and I don't understand how this works.
x = Px + tdx
y = Py + tdy
and
\(\displaystyle y = dy\tfrac{x-Px}{dx} + Py\)
and it become a
\(\displaystyle 0 = \tfrac{y-Py}{dy} - \tfrac{x-Px}{dx}\)
and then it become a
= (-dy)x + (dx)y + (dyPx - dxPy)
= ax + by + c
I really don't understand is that how I can get
(-dy)x + (dx)y + (dyPx - dxPy)
from
\(\displaystyle 0 = \tfrac{y-Py}{dy} - \tfrac{x-Px}{dx}\)
I always get this
\(\displaystyle \frac{(y-Py)dx - (x-Px)dy}{dydx}\)
I don't know how to get rid of dydx in the bottom.
Thanks for help