00:01
In this problem, we are asked to prove the statements that they give us.
00:04
And to do this, we know that the function, or the expression p is equal to the partial of f with respect to x.
00:14
Now, we can also write this in the way that p is equal to the partial of f with respect to x, and we know that q is the partial of y, or excuse me, the partial of f with respect to y.
00:26
And so we can also write q as the partial of f with respect to y, and we know that r is equal to the partial of f with respect to z, and so we can write it as the partial of f with respect to z.
00:40
Now knowing all of this, we have to prove that the partial of y with the respect, excuse me, the partial of p with respect to y is equal to the partial of q with respect to x.
00:50
Now, because we know that p is partial of f with respect to x, we know that that is p, and so we would take the partial with respect to y of that.
01:06
And so when we do this, we get the partial squared of f over the partial of y and the partial of x.
01:25
And we can actually rewrite the bottom to be the partial squared of f over the partial of x times the partial of y.
01:39
And so by the partial squared of f, i just mean the second partial of f.
01:42
It's not actually squared...