00:01
In this exercise you have a wave function, psi of x, y, and z that is given in a cartesian coordinate as a times x, times z to the minus alpha x squared, times e to the minus beta, y squared, times e to the minus gamma z squared, where a, alpha, beta, and gamma are positive and real.
00:30
And in question a, our goal is to find what is the x position, that we're going to call x0, where it's most probable to find the particle.
00:45
So notice that the probability density, p of x, y, and z, is equal to the square of the magnitude of the wave function.
01:01
And the square of the wave function is a squared, x squared, e to the minus 2, alpha, x squared, e to the minus beta, 2 beta, i'm sorry, y squared, e to the minus 2, gamma z squared.
01:21
Notice that this is equal to x squared, e to the minus 2, gamma, x squared times the function, f of y, and and z.
01:33
Okay? and since we want to find the most probable value of x, then we want the probability to be maximized.
01:43
So in order to find the maximum, i'm going to differentiate the probability with respect to x and search for the point where the derivative of p with respect to x is equal to 0.
01:58
Notice that the pdx is equal to according to the multiplication rule, 2x times z to the minus 2 alpha x squared f of y z plus x squared times e to the minus 2 alpha x squared times the derivative of what's inside the exponential by the chain rule.
02:27
So we have minus 4 alpha x times f of y z.
02:35
And we want this to be zero.
02:38
Okay, so i'm just going to factor out to, i'm going to factor out to x, e to the minus 2 alpha x squared, f of y z times 1 minus 2 alpha x squared...