Question

cos2x = 0

Solve.

Answer 1

Are you ready?

Answer 2

Do you need a general solution? Was there an interval given?

Answer 3

@Timer Are you there? Or do you not want me to teach you how to solve these problems?

Answer 4

Sorry I was solving the rest of my assignment.

Answer 5

That was all I was given, cos2x = 0. And it says solve.

Answer 6

do I do this:

2x = cos-1 0

2x = 0.57

2x = pi/2

x = pi/4

Now for my other point is where I am having trouble. I orginally thought since it is cos then I have to get it into the 4th quadrant which i thought was 7pi/8 which is wrong...What is the right answer?

Answer 7

No, let 2x = θ, then

cos θ = 0

Now from the cosine graph, where does cos θ = 0?