How do you solve #cos(2x)=1/2# and find all exact general solutions?

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Answer 1 · 2016-12-06T06:13:42

The general solutions are #S={pi/4+kpi,-pi/4+kpi}#, #k in ZZ#

The solutions for

#costheta=1/2#

are #theta={pi/2+2kpi,-pi/2+2kpi} #

Here,

#cos(2x)=1/2#

So, #2x={pi/2+2kpi,-pi/2+2kpi}#

#x={pi/4+kpi,-pi/4+kpi}#

and #k in ZZ#