Help! I don’t know how to do any of that :/

Lindsay is creating a bridge out of dried pasta and glue. in her plans, she sketches the graph to determine the lengths of the noodles, in centimeters, needed for the arch to increase the length of the bridge in 1 centimeter increments.which function did lindsay use to create her design? f(x) = (x – 5)2 + 8 f(x) = –(x + 5)2 + 8 f(x) = 0.5(x + 5)2 + 8 f(x) = –0.5(x – 5)2 + 8

In triangle abc, the length of side ab is 12 cm, the length of side bc is 5 cm, and the length of side ca is 9 cm. find the measure of angle a using the law of cosines.

The table represents a linear function. what is the slope of the function? –6 –4 4 6