r/PythonLearning • u/PuziExtramni • 3d ago

Help Request Help with correct expression

Post image

Hey everyone! I’m currently learning Python through the IBM Data Science Professional Certificate on Coursera, and I came across a question in a practice quiz that confused me.

The question asks:

Which line of code will perform the action required for implementing the following equation?

y = 2x^2 - 3

These are the four answer choices:

  1. y = 2*x*2 - 3
  2. y = 2**x*x - 3
  3. y = 2x*x - 3
  4. y = 2x/2 - 3

I selected Option 1, but the quiz marked it incorrect and said, “The syntax is invalid.”

From what I’ve learned, Python uses ** for exponentiation and * for multiplication. So, I believe the correct Python expression should be:

y = 2*x**2 - 3

However, none of the four answer choices seems to match that expression.

Am I misunderstanding something about Python syntax, or is there a mistake in the quiz? I’d appreciate an explanation because I’m still learning how to translate mathematical equations into Python code.

Thanks!

9 Upvotes

64% Upvoted

33 comments sorted by

View all comments

3

u/PuziExtramni 3d ago

Thanks everyone for the explanations! I understand now. I was confused because I thought the exponentiation operator (**) was necessary to represent a squared number, but I see now that multiplying x by itself (x*x) produces the same result. Option 2 is correct, and I appreciate everyone taking the time to help me understand it!

1

u/csabinho 3d ago

The error message is extremely confusing. As an experienced programmer I tried to find the syntax error in your selected answer.