How do you solve $Cos ( x + pi/6 ) = -0.5$ over the interval 0 to 2pi?

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Answer 1 · 2016-07-14T23:59:56

$pi/2,(7pi)/6$

$cos(x+pi/6)=-1/2$

$=>cos(x+pi/6)=-cos(pi/3)$

$=>cos(x+pi/6)=cos(pi-pi/3)=cos(2/3pi)$

$=>x+pi/6=2/3pi$

$:.x=(2pi)/3-pi/6=pi/2$

Again

$=>cos(x+pi/6)=-cos(pi/3)$

$=>cos(x+pi/6)=cos(pi+pi/3)=cos(4/3pi)$

$=>x+pi/6=4/3pi$

$:.x=(4pi)/3-pi/6=(7pi)/6$

How do you solve Cos ( x + pi/6 ) = -0.5 Cos ( x + pi/6 ) = -0.5 over the interval 0 to 2pi?