Find x if cos2x = cos 60* cos 30* +sin60* sin30* (* = degree) pl help I’ll mark as brainlest

Identify a1 and r for the geometric sequence an= -256(-1/4) n-1

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.)

Through: (-3,-3) parallel to y= 7/3x+3