(a) If there is a scalar function f(x, y) such that ∇ f(x, y) = x² i + y² j, then
∂f/∂x = x²
∂f/∂y = y²
Integrating both of these equations with respect to x and y (respectively) gives
f(x, y) = 1/3 x³ + g(y)
f(x, y) = 1/3 y³ + h(x)
Differentiating with respect to the other variable gives
∂f/∂y = g'(y) = y²
∂f/∂x = h'(x) = x²
so it follows that
f(x, y) = 1/3 x³ + 1/3 y³ + C
for some constant C.
(b) By the gradient theorem,

Answer:
8y(7x^3-4x+2)
Step-by-step explanation:
No.
4286 / 6= 714.33333333333
I think bank 4 hope i am right
Answer:
The number is 45
Step-by-step explanation:
Let number = x
2/3 x = 30
x = 30/2/3
x = 30×3/2
x = 90/2 = 45
The number is 45
2/3 ×45= 90/3 = 30