is a real number that satisfies the equation
How many such 's are there?
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Obviously, x = 2 is a solution, but also x = 4 since 2 4 = 4 2 .
2 x > x 2 for x > 4 ,so there are no other solutions.
For x < 2 , there is one additional negative solution. 2 0 = 1 > 0 = 0 2 but then 2 − 1 = 2 1 < 1 = ( − 1 ) 2 . By the Intermediate Value Theorem , there must be one solution in between and since x 2 is strictly decreasing for x < 0 , this is the only negative solution
Therefore, there are a total of 3 solutions.