2.2.90 Derivatives and Differentials
Condition: to prove that the function \ (f (x, y) \) is differentiated at a given point \ (O \) and calculate the differential at this point. \ [f (x, y) = \ left \ {\ begin {array} {c} x^{2}+y^{2} \ sin {1} {2}+y^{2}}, x {2}+y^{2} {2} {2 \ neq 0 \\ 0, x^{2}+y^{2} = 0 \ End {Array}, O (0.0) \ Right. \]
Calculation of derivatives and differentials of first and Higher Orders of Function of One and Many Varia Bybles, Including Partial Derivatives.