Posted by Megan on Thursday, August 27, 2009 at 10:31am.
Megan, look at how your post came out.
what is *2/2 supposed to be?
I have a feeling you mean √2/2
If so, then
since the cosine is positive in quadrants I and IV
2x = 45º or 2x = 315º
then x = 22.5º or x = 157.5º
but we know that the period of cos(2x) is 180º, so by adding 180 to each of our answers we get the other solutions in the given domain, or
x = 202.5º
x = 337.5º
just noticed that you probably wanted the solutions in radians, that would be
pi/8, 7pi/8, 9pi/8, and 15pi/8
Related Questions
Pre Calc - Solve the equation on the interval [0,2pi). cos2x=(*2/2)
Pre-Calculus - Find all solutions to the equation in the interval [0, 2pi) cos4x...
Precalculus - Please help!!!!!!!!!!! Find all solutions to the equation in the ...
pre calc - cos2x=cosx in interval of [0,2pie]
calculus - Solve for x on the interval (0, 2pi] (sin2x + cos2x)^2 = 1
Pre-Calc/Math - Use factoring, the quadratic formula, or identities to solve cos...
calculus - Find all solutions to the equation in the interval [0,2pi) Cosx-cos2x
PRE CALC PLEASE HELP!!!!!!!! - find the solutions of the equation that are in ...
Trig. - Can someone please help me with this? Find all solutions to the equation...
Pre-calc - The question is solve for cosx= 0.60 on the interval [0,2pi). The ...
For Further Reading
