I need help with these questions for Working with Standard and Vertex Forms of the Quadratic Function, the first image is the instructions for the questions and the rest of the images have been labelled and put in order of the questions:

Which sum or difference identity would you use to verify that cos (180° - ∅) = -cos ∅? a. sin (α -β) = sin α cos β – cos α sin β b. cos (α -β) = cos α cos β – sin α sin β c. cos (α -β) = cos α cos β + sin α sin β d. sin (α + β) = sin α cos β + cos α sin β

Find the roots of the equation below. x^2 - 6 + 9 = 0

Which is the solution to the inequality? 2 3/52 1/15 b< 3 2/15 b> 3 2/15