Do Parametric Equations x=t^2 and y=t^2 Describe a Line?

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The parametric equations x=t^2 and y=t^2 do not describe the line y=x, as they represent a parabola instead. When y is a function of t and x is also a function of t, y is not necessarily a function of x due to the potential for multiple t values yielding the same x. The equations x=cos(t) and y=cos^2(t) do not describe the parabola y=x^2, as the cosine function limits the range of x and y to values between -1 and 1. Proper representation of the function is crucial for clarity in mathematical discussions. Understanding these relationships is essential for mastering parametric equations.
teffy3001
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i have a couple questions that confuse me that would help me on doing my homework on parametric equations...

do the parametric equations x=t^2 and y=t^2 describe the line y=x?
and if y is a function of t and x is a function of t, then is y a funcion of x?
and last, does x=cos t, y=cos^2(t) describe the parabola y=x^2?

these arent my homework questions, but any help or explanation of this would really help me out...thanks : )
 
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teffy3001 said:
i have a couple questions that confuse me that would help me on doing my homework on parametric equations...

do the parametric equations x=t^2 and y=t^2 describe the line y=x?
and if y is a function of t and x is a function of t, then is y a funcion of x?
and last, does x=cos t, y=cos^2(t) describe the parabola y=x^2?

these arent my homework questions, but any help or explanation of this would really help me out...thanks : )
The first question: Yes;
the second question: No.

The cosine function restricts what values x and y can be. Cosine can only be between -1 and +1.

You want to represent your y function as (cos(t))^2 unless you know how to use proper typesetting, such as TEX or something.,
 
oh okay thanks a lot...so then to the last question though, the answer would be no? I am just making sure...
 
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Since ##px^9+q## is the factor, then ##x^9=\frac{-q}{p}## will be one of the roots. Let ##f(x)=27x^{18}+bx^9+70##, then: $$27\left(\frac{-q}{p}\right)^2+b\left(\frac{-q}{p}\right)+70=0$$ $$b=27 \frac{q}{p}+70 \frac{p}{q}$$ $$b=\frac{27q^2+70p^2}{pq}$$ From this expression, it looks like there is no greatest value of ##b## because increasing the value of ##p## and ##q## will also increase the value of ##b##. How to find the greatest value of ##b##? Thanks

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