We know that the inside of a square root has to be positive. So we know that 16 -, X ^2 has to be greater than or equal to 0. So negative X ^2 has to be greater than or equal to -16 X squared. If we divide by a -1 has to be less than or equal to 16. Now when we take and get rid of the square root, we actually or when we take and get rid of the square, we have to square root it. But we have to remember that that square had a positive and a negative case. So what we're really going to say is it has to be negative, the absolute value of sqrt 16 less than or equal to X, less than or equal to the absolute value of 16. So we know that -4 less than or equal to X, less than or equal to four. For the domain portion, writing an interval notation, we're going to use a bracket -4, 4 bracket. Then it also asks for the range and the range, if we think about these are the only possible values we can put in. If I stick in -4 I'm going to get out zero. If I put in four, I'm going to get out zero. If I put in zero, I'm going to get out four. So we're going to get all of the possible values from zero to four. So the range is going to be zero to four. If we thought about graphing this, this is actually the graph of 1/2 a circle from -4 to four for the domain and zero to four for the range.