my trying to prove a point

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luvmykids911

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Nov 12, 2005
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i'm a mom trying to tell my daughter she is wrong, she has this problem:

The graph of the relation x^3 + y^3 = 1 is a (an)


she said it is a straight line, i am not sure she is right. i havent been in math for quite a few years so I may be wrong, if anyone knows what is is example, a point, circle, parabola ect could you please let me know. thanks!
 
yeah that is what i told her she is deadset her teacher said it was. Let me tell her this. le tme see what else she thinks it could be. could it be one of these?

circle
ellipse
hyperbola
parabola
 
What is her reasoning as to why she thinks it's a straight line? Did she use any definitions? If so, provide them.
 
If you have a 16 year old daughter, you know how set in their ways they can be. She isn't home right now she is at school, but lastnight she said she said the teacher said so. I told her that the teacher needs to go back to school because that is wrong. She said she would look into it today but it got me wondering what the real answer is so that is why I came on here, my husband didn't know either.
 
Hello, luvmykids911!

This is an awful problem . . . even using Calculus!

i'm a mom trying to tell my daughter she is wrong, she has this problem:

The graph of the relation \(\displaystyle x^3\,+\,y^3\:=\:1\) is a (an) _____. . I don't think it has a name!
She said it is a straight line, i am not sure she is right.
Click to expand...
Your instincts are correct!

For a straight line, both \(\displaystyle x\) and \(\displaystyle y\) must be to the first power,
. . and this equation has them both cubed.

If her teacher insists it's a straight line, he/she should seek profession help.
The only other explanation is a typo . . . somehow!
 
hello soroban,

Thanks I knew I stil had something.

Anyways my daughter is home and I was able to copy it down before she goes back to school, this is the entire problem. SHe has math 7th period so yeah,

The graph of the relation x3 + y3 = 1 is a (an)

point, straight line, pair of intersecting straight lines, circle, ellipse, hyperbola, parabola or none
 
It's close to "straight" for x < -1, but not close, otherwise. Go with "none". Plot points on (-1,1) to prove it.
 
To be fair, this sounds more like a "teacher" problem than a "teenager" problem. :roll:

Your daugher, attitude and all :wink: , is learning; the teacher is supposed to know.

Eliz.
 
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