rightA.x=7/6pi, 11/6pi

these solutions work but there are others as well. Remember that if = a thenB.x=pi/4 7/4pi

C.x=pi/6 7/6pi 2pi pi

You have lost a minus sign somewhere here, you should have ended up with cos x = 0 or cos x = -1/2, but the good news is that you appear to know what you are doing.D.x=pi/2, 3/2pi pi/3 5/3pi

=A.Cos75(degrees)

B.Sin15(degrees)

C.tan345(degrees)

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