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 $k in ZZ$

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