SOLUTION: How to: "Find the number of solutions of the equation cos^2-1=0 in the interval [0, 2pi] I began by using the Pythagorean identity and replaced cos^2 by (1-sin^2x). The proble

Question 888438: How to: "Find the number of solutions of the equation cos^2-1=0 in the interval [0, 2pi]
I began by using the Pythagorean identity and replaced cos^2 by (1-sin^2x).
The problem then looked like: (1-sin^2x)-1=0.
I canceled out the 1 & -1 making the problem: -sin^2=0
I do not know where to go from here, or if I have been doing the problem right so far.
Answer by Fombitz(32388) (Show Source): You can put this solution on YOUR website!
You're alright up to there although you could have just stayed with cosine.

Multiply both sides by (-1).

Take the square root of both sides.

Now, which values of give you a value of ?
There are two of them.

and

.
.
.
For the cosine,

Also, two solutions.
and

RELATED QUESTIONS
Find all solutions t in the interval [0 , 2pi] to the equation sin(2t) = square root of 2 (answered by lwsshak3)

find all solutions t in the interval (0, 2pi) to the equation sin(2t)=square root of 2... (answered by stanbon)

ind all the solutions of the equation in the interval 0 2pi cos 2 theta= 1-3 cos... (answered by lwsshak3)

find all solutions of equation in the interval [0, 2pi) 2 cos theta+square root 3 = 0 (answered by Fombitz)

Find all solutions of each equation in the interval [0, 2pi)... (answered by lwsshak3)

Find the solutions of the equation that are in the interval [0, 2pi). cos u + cos 2u = (answered by lwsshak3)

Find all the solutions t in the interval (0, 2pi) to the equation sin (2t) = sqare root (answered by lwsshak3)

Find all solutions of each of the equations in the interval (0, 2pi) cos(x- pi/2) +... (answered by lwsshak3)

Find all solutions in the interval [0, 2pi) Cos^2 (x/2) = cos^2... (answered by lwsshak3)