C2 Trig Watch
a) cos (x + 40°) = 0.3,
b) 2 + tan 2x = 0.
Remember cos is positive, so values are in the 1st and 4th quadrants.
b) tan 2x = -2, -360 ≤ 2x ≤ 360 and then solve like in a)
Reply back if your still stuck, with the bits you dont understand.