Question

f(x) = $a^x$ (where a >1) defined on f: R $\to (0,\infty )$ is -

• A. One One into function
• B. One one onto function
• C. Many one into function
• D. Many one onto function

Answer 1

The correct option is B

One one onto function

We know that the given function is one one.(no line parallel to x-axis cuts the graph at more than one point). So, the correct options could be A or B.

Now we have to check whether the function is onto or into. The co-domain given for that function is (0,$\infty$) . And we know that the f(x) = $a^x$ranges from (0,$\infty$). So the range and codomain is equal. And the function is onto. Hence the correct option will be B.