Can anyone help me to solve this question?

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

Each equation given below describes a parabola. which statement best compares their graphs? x = 2y^2 x = 8y^2

How much dextrose 70% must be mixed with dextrose 5% to prepare 1,000 ml of dextrose 20%?