Many students think that sinx/x=1 (not 0) but they are wrong! Think about the fact that the numerator, sinx, is always between -1 and 1 inclusive while the denominator can be say 10000. A number between -1 and 1 when divided by 10,000 is not 1 (or 0-usually). What the statement should be, as Dr Peterson pointed out, is that as x approaches 0, sinx/x approaches 1