At what value of the variable [[$ x $]] does the value of the function become 16?

a) [[$ f(x) = x^2 $]]



Answer: When [[$ x = $]] , the value of the function is 16.

b) [[$ f(x) = 4x - 4 $]]



Answer: When [[$ x = $]] , the value of the function is 16.

c) [[$ f(x) = \displaystyle\frac {x} {2} $]]



Answer: When [[$ x = $]] , the value of the function is 16.

d) [[$ f(x) = \displaystyle\frac {1} {2x} $]]



Answer: When [[$ x = $]] , the value of the function is 16.