engineering recuitment ISRO Scientist Mechanical Mock Test Engineering Mathematics Calculus Differentiability
If f (x, y) = x3y – xy3, then what is the value of \(\left[ {\frac{1}{{\frac{{{\rm{df}}}}{{{\rm{dx}}}}}}{\rm{\;}} + \frac{1}{{\frac{{{\rm{df}}}}{{{\rm{dy}}}}}}} \right]\) x = 1, y = 2?
1
13/18
2
-9/18
3
9/22
4
-13/22