The slope of the secant line is equal to the value of the function at this point, f of x naught plus h, minus the value of the function here, minus f of x naught. So that just tells us the change in y. It's the exact same definition of slope we've always used. Over the change in x. And we can simplify this. We have x naught plus h, minus x naught. So x naught minus x naught cancel out.