When x is less than or equal to zero, f is one minus two sine of x. When x is greater than zero, f is e to the negative four x. Show that f is continuous at x equals zero. So for something to be continuous at x equals zero, let's think about what has to happen. So if I have a function here, so that is my x-axis, and let's say this is my y-axis, and we care about what happens at x equals zero. So x equals zero there, and let's say that this is our function. Let's say that this is our function.