Question 1116153
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cos(4t) = 0 =====>


4t = {{{pi/2 + k*pi}}},  where k is any integer  k = 0, +/-1, +/-2, . . .  ====>


t = {{{pi/8 + k*(pi/4)}}},  where k is any integer  k = 0, +/-1, +/-2, . . . .


<U>Answer</U>.  The given equation has infinitely many solutions  t = {{{pi/8}}} + {{{k*(pi/4)}}},  where k is any integer  k = 0, +/-1, +/-2, . . . .
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