# Resolved: Mathematics Course Exam: Question 9 - Explanation of correct answer

The question looks at two vectors in the format a = [ x y ] and b = [ -x -y ]. We are asked to identify the correct statement. Now, upon reviewing the answers, according to the explanation of correct answer, we are told that statement a) is correct that b is a reflection of a, with respect to the graph y = -x.

Imho, I believe this not to be correct, as the reflection of a with respect to the graph y = -x is [ -y -x ], not [ -x -y ]. I believe in order for the statement to be correct, it should read: "Geometrically represented, b is a reflection of a, with respect to the origin (0,0)", or, "Geometrically represented, b is a 180° rotation of a, with respect to the origin (0,0)". Another option, is to change the question so that b is in the format [ -y -x ].

Thank you for these amazing courses!

Hey Leon,

You are completely right, thank you for letting us know! We will correct the question and revise the exam.

Kind regards,

365 Hristina

Hi Hristina,

Thank you for your quick response.

I'm glad to have pointed this out, so that it can help others.

Best regards,

Leon

The correction is still not done regarding changing the point of reflection. The error still persists due to which the chosen answer is marked incorrect. Can you please do the same and confirm?