Final answer:
The magnitude of the electric field in a region with a given potential can be calculated using the equation E = -dV/dx. In this case, the potential is given by V = ax^2 + b. By differentiating the potential with respect to position, the electric field is found to be 300x V/m.
Step-by-step explanation:
The electric field, E, is related to the potential, V, by the equation:
E = -dV/dx
where dV is the change in potential along the x-direction and dx is the change in position along the x-direction.
In this case, the potential is given by: V = ax^2 + b
So, the electric field can be calculated as:
E = -dV/dx = -d/dx(ax^2 + b)
Since b is a constant, the derivative of b with respect to x is 0. Therefore, the electric field becomes:
E = -d/dx(ax^2) = -2ax
Substituting the given values of a and b:
E = -2(-150)x = 300x
Thus, the magnitude of the electric field is 300x V/m.