How do you solve the following equation 2 cos x - 1=02cosx1=0 in the interval [0, 2pi]?

1 Answer
Jul 31, 2016

The solutions are x=pi/3 and x=5pi/3x=π3andx=5π3

Explanation:

2cos(x)-1=02cos(x)1=0

Get rid of -1 from left side

2cos(x)=12cos(x)=1

cos(x)=1/2cos(x)=12

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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/3x=π3andx=5π3