#2: This function is not defined if the denominator = 0. So, steal the denom. and set it = to 0, and then solve the resulting eqn: 3x-1=0, 3x = 1, x = 1/3.
The domain is the set of all real numbers except for x = 1/3. The range is the set of all real numbers except for y = 0.
#4: this function will not be defined if 16-x^4 is less than 0.
so you must solve the inequality x^4 ≤ 16. Take the 4th root of both sides. The domain is (-2, 2). By all means, check. Suppose x = 1.5. is x^4≤16?
The smallest value y can have is zero, which occurs when x = plus or minus 2.