How do you find all solutions if 0 ≤ θ < 2π for sec 3x = −1?

1 Answer
Binayaka C.
Sep 4, 2016

Solutions are x=60^0,180^0,300^0

Explanation:

sec3x=-1 or 1/(cos3x)=-1 or cos 3x = -1; cos 180= -1 :. 3x=180 :.x=60^0
for 0<=x<=360 or 0<=3x<=1080:. cos(180+360)= -1 :. 3x=540 or x=180^0 ; cos(540+360)= -1 :.3x=900 or x=300^0So solutions are x=60^0,180^0,300^0[Ans]

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