Question #59822

1 Answer
Oct 11, 2017

For #-pi <= x <= pi#:

#x = -2.35619449, 2.35619449#

Explanation:

#2cos(x/3) - sqrt(2) = 0#

#2cos(x/3) = sqrt(2)#

#cos(x/3) = sqrt(2)/2#

#x/3 = cos^-1(sqrt(2)/2)#

#x = 3 * cos^-1(sqrt(2)/2)#

The graph below represents #y = 2cos(x/3)# and #y = sqrt(2)#

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