This set of Python Developer Questions & Answers focuses on “Mathematical Functions”.

1. What does the function math.frexp(x) return?

a) a tuple containing of the mantissa and the exponent of x

b) a list containing of the mantissa and the exponent of x

c) a tuple containing of the mantissa of x

d) a list containing of the exponent of x

View Answer

Explanation: It returns a tuple with two elements. The first element is the mantissa and the second element is the exponent.

2. What is the result of math.fsum([.1 for i in range(20)])?

a) 2.0

b) 20

c) 2

d) 2.0000000000000004

View Answer

Explanation: The function fsum returns an accurate floating point sum of the elements of its argument.

3. What is the result of sum([.1 for i in range(20)])?

a) 2.0

b) 20

c) 2

d) 2.0000000000000004

View Answer

Explanation: There is some loss of accuracy when we use sum with floating point numbers. Hence the function fsum is preferable.

4. What is returned by math.isfinite(float(‘inf’))?

a) True

b) False

c) None

d) error

View Answer

Explanation: float(‘inf’) is not a finite number.

5. What is returned by math.isfinite(float(‘nan’))?

a) True

b) False

c) None

d) error

View Answer

Explanation: float(‘nan’) is not a finite number.

6. What is x if x = math.isfinite(float(‘0.0’))?

a) True

b) False

c) None

d) error

View Answer

Explanation: float(‘0.0’) is a finite number.

7. What is the result of the following?

>>> -float('inf') + float('inf')

a) inf

b) nan

c) 0

d) 0.0

View Answer

Explanation: The result of float(‘inf’)-float(‘inf’) is undefined.

8. What is the output of the following?

print(math.isinf(float('-inf')))

a) error, the minus sign shouldn’t havve been inside the brackets

b) error, there is no function called isinf

c) True

d) False

View Answer

Explanation: -float(‘inf’) is the same as float(‘-inf’).

9. What is the value of x if x = math.ldexp(0.5, 1)?

a) 1

b) 2.0

c) 0.5

d) none of the mentioned

View Answer

Explanation: The value returned by ldexp(x, y) is x * (2 ** y). In the current case x is 1.0.

10. What is returned by math.modf(1.0)?

a) (0.0, 1.0)

b) (1.0, 0.0)

c) (0.5, 1)

d) (0.5, 1.0)

View Answer

Explanation: The first element is the fractional part and the second element is the integral part of the argument.

**Sanfoundry Global Education & Learning Series – Python Programming Language.**

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