- #1
guitarphysics
- 241
- 7
I feel kind of ridiculous making this post, but here we go:
What would be the correct answer to this question;
Choose all the number sets (natural, integer, rational, or irrational were the only options given) that
-√81 belongs to, and show how you found your answer.
What I said was this:
-√81=-(plus or minus 9)=-9 or 9.
Therefore, -√81 is a an integer and a rational number.
My teacher (who hates me) said in front of the whole class that I got this wrong. She said I got the final answer right, but that when she asked for the square root of 81, all she was asking for was the principal square root, so my work was incorrect (if I had only taken the principal square root, I of course would have gotten the same number sets, so the final answer was right).
Is it true that when they ask you for the square root of a number, you should only give the principal square root? And if so, do you think she's justified in taking off 1 out of the 2 points that problem was worth?
Thanks
PS. I know how ridiculous it is that I'm in 10th grade and this is what we're doing in math class...
What would be the correct answer to this question;
Choose all the number sets (natural, integer, rational, or irrational were the only options given) that
-√81 belongs to, and show how you found your answer.
What I said was this:
-√81=-(plus or minus 9)=-9 or 9.
Therefore, -√81 is a an integer and a rational number.
My teacher (who hates me) said in front of the whole class that I got this wrong. She said I got the final answer right, but that when she asked for the square root of 81, all she was asking for was the principal square root, so my work was incorrect (if I had only taken the principal square root, I of course would have gotten the same number sets, so the final answer was right).
Is it true that when they ask you for the square root of a number, you should only give the principal square root? And if so, do you think she's justified in taking off 1 out of the 2 points that problem was worth?
Thanks
PS. I know how ridiculous it is that I'm in 10th grade and this is what we're doing in math class...