First of all, let's just think about the value of the function there. So remember, we're doing part a. f of 0 is equal to, we're going to use this first case, because that's the case for x is less than or equal to 0. So f of 0 is going to be equal to 1 minus 2 sine of 0. Well, sine of 0 is 0. 2 times 0 is 0. So this whole thing is 0. 1 minus 0 is 1.