# Question #59f7b

##### 1 Answer

Jan 2, 2018

#### Answer:

See the explanation.

#### Explanation:

If a function **bijective**, or **one-to-one onto**.

The figure is the example of a bijective function. If you choose one element from the right elipse, you can know the corresponding element in the left oval.

It is a good way to draw a graph of the function if you want to know whether it is bijective.

graph{2x+1 [-5, 5, -5, 5]}

graph{x^2 [-5, 5, -5, 5]}

Then, how about

graph{xtan((pix)/2) [-1, 1, -5, 5]}

The function

For example,

Therefore, it has no inverse.