Write the equation for the inverse of the function. y= cos(x - pi/2)

Which ordered pair (c,d) is a solution to the given system of linear equations- c+2d=13 -9c-4d=-15

Determine whether the quadrilateral below is a parallelogram. justify/explain your answer (this means back it up! give specific information that supports your decision. writing just "yes" or "no" will result in no credit.)

Find the solution of this system of equation -7x+y=-20 9x-3y=36