(a) 2 (b) -1
These are the actual answers. I just added an explanation for the plus and minus signs against the numbers, so 1⁺ means the positive or right side of x=1 and 1⁻ means the negative or left side of 1. Notice that 1⁺ should not be confused with +1 and 1⁻ should not be confused with -1. The superscripted signs are usually often used in limits to show whether the limit is approaching from the positive or negative side of the value. For example, x=0.999 is close to x=1 from the left side while x=1.001 is close to x=1 from the right side. In limits this distinction is, or can be, important.