# Unimodal PDF having non-unique mode

I am learning statistics from this book and in Exercise 2.27 (on page 79) I came across the term unimodal. As I understand, unimodal means having only one value of mode. But in this question, in part (b), it is asked to give an example of unimodal PDF in which mode is not unique. So how can a PDF be unimodal when its mode is not unique? Or, have I misunderstood something here? Please explain.

• The question uses a highly nonstandard definition of unimodality that allows for, e.g. the uniform distribution to be called unimodal. – user10354138 Sep 27 '18 at 18:37
• @user10354138 So you mean if a continuous PDF has a flat peak, the PDF will be unimodal? – Ankit Seth Sep 27 '18 at 18:51
• Only if you define it as in this question or equivalent. – user10354138 Sep 28 '18 at 21:13