(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,

The given trinagle is a right angle triangle. let the missing side be x. To find x, we would apply the pythagorean theorem which is expressed as
hypotenuse^2 = one leg^2 + other leg^2
From the triangle,
hypotenuse = 14
one leg = 9
other leg = x
Thus, we have
![\begin{gathered} 14^2=9^2+x^2 \\ 196=81+x^2 \\ x^2\text{ = 196 - 81 = 115} \\ x\text{ = }\sqrt[]{115} \\ x\text{ = 10.72} \end{gathered}](https://tex.z-dn.net/?f=%5Cbegin%7Bgathered%7D%2014%5E2%3D9%5E2%2Bx%5E2%20%5C%5C%20196%3D81%2Bx%5E2%20%5C%5C%20x%5E2%5Ctext%7B%20%3D%20196%20-%2081%20%3D%20115%7D%20%5C%5C%20x%5Ctext%7B%20%3D%20%7D%5Csqrt%5B%5D%7B115%7D%20%5C%5C%20x%5Ctext%7B%20%3D%2010.72%7D%20%5Cend%7Bgathered%7D)
To the nearest tenth, the length of the third side is 10.7
Answer:
20cm or A
Step-by-step explanation:
pythagorean theorem
25^2=15^2+b^2
625=225+b^2
b^2=400
b=20
Answer:
A
Step-by-step explanation:

Expand parentheses:

Move all y's to one side and numbers to the other:

Divide both sides by -6. Since you are dividing both sides by a negative number, you need to flip the comparator:

Hope this helps!