Question

\[\sum_{}^{} [(f(x+dx,y) - f(x,y))\times(f(x,y+dy)-f(x,y))]\]
will this give me the area of the graph f(x,y)?

Answer 1

shouldn't the \(\text dx\)'s be \(\Delta x\)'s?

Answer 2

I bet it's a multivariate function f(x,y)

Answer 3

i think it s a yes

Answer 4

it seems like summation of
\[ \sum f_x \Delta x\times f_y \Delta y \]
should be \[ \sum \sum \Delta x \Delta y\]

Answer 5

c graph is a function of x nd y....so take include z axis to.....now....for small variation of x nd y...... above equation is the sum of small squares......