The diagram shows a mooting trame ABCD. AB = 7m, BC - 5m, DB-3 m, angle ABD = angle DBC = 90°. 3 m B 50 (a) Calculate the length ofAD. (b) Calculate the size of angle DCB.

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