Which two consecutive whole numbers is the value of square root of 21 between? ( put step by step how you got the answer)
4 and 5
10 and 11
21 and 22
42 and 43

Astudent draws two parabolas on graph paper. both parabolas cross the x-axis at (–4, 0) and (6, 0). the y-intercept of the first parabola is (0, –12). the y-intercept of the second parabola is (0, –24). what is the positive difference between the a values for the two functions that describe the parabolas? write your answer as a decimal rounded to the nearest tenth