Question

PLEASE HELP MEEEEEEEEE

Answer 1

9514 1404 393

Answer:

A, B

Explanation:

The equation is equivalent to ...

cos(x -π/7) = -(√2)/2

x -π/7 = arccos(-(√2)/2) = {3π/4, 5π/4} . . . . . cosine is negative in QII and QIII

x = {3π/4 +π/7, 5π/4 +π/7} +2nπ . . . . . matches A and B