Question

Which of the following is a logarithmic function?
y = 0.25x
y = x Superscript 0.25
y = log Subscript 0.25 Baseline x
y = (0.25) Superscript x

Answer 1

y = log_{0.25} x

Reason: a logarithmic function has the form y = log_b x (the inverse of an exponential). The others are: y = 0.25x (linear), y = x^{0.25} (power/root), and y = (0.25)^x (exponential).