PQ + QR = PR
7 + 10 = PR
17 = PR
The answer is 17
(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:
i think -3
Step-by-step explanation:
5 = -4(-2)+b
5=8+b
5-8=8-8+b
-3=b
To find a perpendicular line, the slope is opposite reciprocal. The slope would be -4x.
Put in point slope form:
y - 7 = -4(x - 2)
y - 7 = -4x + 8
y = -4x + 15
(line perpendicular to given equation and goes through the point)
Hope this helps!! :)