Simple types and strings (1) X26735

You have to program several functions. In each case, few lines of code are enough.

1. Write a function @drawH(n)@ that given an odd integer $n\ge 3$ prints a letter H of size $n$ formed with symbol . Follow the pattern of the example below.

2. Write a function @area_circle(r)@ that given a float number $r\ge 0$ returns, rounded to the hundredth, the area of the circle of radius $r$. Use the pi constant defined in the math module.

3. Write a function @slow_pi_aprox(n)@ that given a non negative integer $n$ computes $4\sum_{k = 0}^n \frac{(-1)^k}{2k + 1}$ rounded to the hundredth.

4. Write a function @is_univariate_number(n)@ that given a non negative integer returns a boolean pointing out whether $n$ is represented using only one digit. For instance $22222$ is univariate but $22322$ is not.

5. Write a boolean function @is_univariate_word(s)@ that given an string $s$ returns True if and only if $s$ is formed using only one letter. For instance word xxXxXXx is univariate but xxXxy is not. We assume $s$ is non empty and all characters of $s$ are letters.

Scoring

Every function counts 20 points.

Sample session