Final answer:
The gradient of pressure (P) between two points (1,2) and (2, 1) is -1. ∇P can be represented as a vector with a magnitude of -1 and a direction pointing in the negative x-axis.
Step-by-step explanation:
To calculate the gradient of pressure (P) between two points (x, y) = (1,2) and (2, 1), we can use the formula:
Gradient of P = (P2 - P1) / (x2 - x1)
Applying the values given:
Gradient of P = (1 - 2) / (2 - 1) = -1
The calculated gradient of P at (x, y) = (1,2) and (2, 1) is -1. To draw ∇P as a vector at these points, we represent the gradient as a vector with a magnitude of -1 and a direction pointing in the negative x-axis.