Eliminate the parameter to find the curve's equation in x and y, and name it. 60 problems with worked solutions; in 60 of them every
equation is proved by a computer algebra system.
6 worked problems
Try each one before opening the solution. Every line is labeled with what checked it. How we verify
✓ Nihil obstat Lines: 1 proved, 1 reviewed. The answer was also checked a second way, without looking at the solution. Reviewers found nothing wrong with the explanation. The full receipt ·
How we verify
The parametric point satisfies the equation for every t.✓ Proved
Answer \( y = x^{2} - 6 x + 7\ (\text{parabola}) \)
✓ Nihil obstat Lines: 1 proved, 1 reviewed. The answer was also checked a second way, without looking at the solution. Reviewers found nothing wrong with the explanation. The full receipt ·
How we verify
Eliminate the parameter from \( \displaystyle x = - t - 2,\ y = 3 t + 3 \), and say what kind of curve it is.
t = (x − -2)/-1; substitute into y.
Reviewed
\[ \left. 3 x + y + 3 \right|_{\substack{ x=- t - 2\\ y=3 t + 3 }} = 0 \]
The parametric point satisfies the equation for every t.✓ Proved
Answer \( y = - 3 x - 3\ (\text{line}) \)
✓ Nihil obstat Lines: 1 proved, 1 reviewed. The answer was also checked a second way, without looking at the solution. Reviewers found nothing wrong with the explanation. The full receipt ·
How we verify
Eliminate the parameter from \( \displaystyle x = - 4 t - 1,\ y = 2 - 4 t \), and say what kind of curve it is.
t = (x − -1)/-4; substitute into y.
Reviewed
\[ \left. - x + y - 3 \right|_{\substack{ x=- 4 t - 1\\ y=2 - 4 t }} = 0 \]
The parametric point satisfies the equation for every t.✓ Proved
Answer \( y = x + 3\ (\text{line}) \)
✓ Nihil obstat Lines: 1 proved, 1 reviewed. The answer was also checked a second way, without looking at the solution. Reviewers found nothing wrong with the explanation. The full receipt ·
How we verify
The parametric point satisfies the equation for every t.✓ Proved
Answer \( y = x^{2} - 4 x + 7\ (\text{parabola}) \)
✓ Nihil obstat Lines: 1 proved, 1 reviewed. The answer was also checked a second way, without looking at the solution. Reviewers found nothing wrong with the explanation. The full receipt ·
How we verify
Eliminate the parameter from \( \displaystyle x = - 2 t - 2,\ y = 2 t \), and say what kind of curve it is.
t = (x − -2)/-2; substitute into y.
Reviewed
\[ \left. x + y + 2 \right|_{\substack{ x=- 2 t - 2\\ y=2 t }} = 0 \]
The parametric point satisfies the equation for every t.✓ Proved
Answer \( y = - x - 2\ (\text{line}) \)
✓ Nihil obstat Lines: 1 proved, 1 reviewed. The answer was also checked a second way, without looking at the solution. Reviewers found nothing wrong with the explanation. The full receipt ·
How we verify