How do you solve the following equation # 2 cos x - 1=0# in the interval [0, 2pi]?

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Answer 1 · 2016-07-31T09:59:23

The solutions are #x=pi/3 and x=5pi/3#

#2cos(x)-1=0#

Get rid of -1 from left side

#2cos(x)=1#

# cos(x)=1/2#

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Use the unit circle Finds the value of x, where cos(x)=1/2.

It is clear that for #x=pi/3 and x=5pi/3. cos (x)=1/2.

so the solutions are #x=pi/3 and x=5pi/3#