For how many integers n is 2^x = n^x ?  Choose the correct answer
A) None	B) One	C) Three	D) Two	E) More than Three
draw a graph with x^2 and 2^x, you'll see 3 intercepts between the 2 curves, but one is in the 2nd quadrant, so it can't be an integer (for integer values of x, 2^x can be an integer only for x&gt;0). Thus 2 are valid, and the answer is Two
<result>D</result>
For how many integers n is 2^x = n^x ?