Use the double angle identity for cosine cos(2a) = 2cos2 a − 1 to derive the half-angle identity.

What is the least common multiple of 6 and 17?

What is the solution to this system of equations? y= 2x - 3.5 x - 2y = -14

Which statements about the system are true? check all that apply. y =1/3 x – 4 3y – x = –7 the system has one solution. the system consists of parallel lines. both lines have the same slope. both lines have the same y–intercept. the equations represent the same line. the lines intersect.