- #1
Titan97
Gold Member
- 450
- 18
My maths teacher taught me a shortcut for finding area bounded by curves of the form: $$|as+by+c|+|Ax+By+C|=d$$
Shortcut:
Let required area be ##A_0## and new area after "transformation" be ##A##
Then, $$A_0\begin{vmatrix}
a& b\\
A& B\end{vmatrix}=A=2d^2$$
All I understood was the ##A=2d^2## part. Its the area of triangle of base=y-intercept and height=x-intercept where x_intercept is c/a and y-intercept is b/a.
I have not even heard the name "jacobian" and I don't know what transformation he was talking about. But the formula worked. I want to learn about Jacobian (the transformation and not the person). How did he get the shortcut? (I did not understand what's given in wikipedia and they have not specified this shortcut)
Shortcut:
Let required area be ##A_0## and new area after "transformation" be ##A##
Then, $$A_0\begin{vmatrix}
a& b\\
A& B\end{vmatrix}=A=2d^2$$
All I understood was the ##A=2d^2## part. Its the area of triangle of base=y-intercept and height=x-intercept where x_intercept is c/a and y-intercept is b/a.
I have not even heard the name "jacobian" and I don't know what transformation he was talking about. But the formula worked. I want to learn about Jacobian (the transformation and not the person). How did he get the shortcut? (I did not understand what's given in wikipedia and they have not specified this shortcut)