Function syntax¶

Solve the following exercises manually. Then, use a Python shell to check your answers.

The authors of the following functions claim that all of them return the double of a given value. Justify which of them are correct and which are not.

def double_1(a):
   b = 2*a

def double_2(a):
   a = 2*a
   return a

def double_3(a):
   return 2*a

def double_4(a):
   a = 3
   return 2*a

Which is the result of the call f('2', 2) ? And the call f('99', '100'). And which is the type of these results ?
```
def f(a, b):
   return a>b
```

Which is the result of the call g(3, 2) ?

def g(a, b):
   a = subtract(b, a)
   b = product(a, b)
   return b, a

def subtract(m, n):
   return m-n

def product(m, n):
   return m*n

What does the following function return for the following calls ?: multiple(10, 2), multiple(10,3), multiple(10, 4) and multiple(10, 5).
```
def multiple(num, x):
    return num%x ==0
```