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Ch.12 - Parametric and Polar Curves
Briggs - Calculus: Early Transcendentals 3rd Edition
Briggs3rd EditionCalculus: Early TranscendentalsISBN: 9780136847243Non è quello che usi tu?Cambia libro di testo
Capitolo 12, Problema 12.R.7a

7–8. Parametric curves and tangent lines
a. Eliminate the parameter to obtain an equation in x and y.
x = 8cos t + 1, y = 8sin t + 2, for 0 ≤ t ≤ 2π; t = π/3

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1
Identify the given parametric equations: \(x = 8\cos t + 1\) and \(y = 8\sin t + 2\) with the parameter \(t\) in the interval \(0 \leq t \leq 2\pi\).
Recall the Pythagorean identity: \(\cos^2 t + \sin^2 t = 1\). This will help us eliminate the parameter \(t\) by expressing \(\cos t\) and \(\sin t\) in terms of \(x\) and \(y\).
Isolate \(\cos t\) and \(\sin t\) from the parametric equations: \(\cos t = \frac{x - 1}{8}\) and \(\sin t = \frac{y - 2}{8}\).
Substitute these expressions into the Pythagorean identity to get an equation involving only \(x\) and \(y\): \(\left(\frac{x - 1}{8}\right)^2 + \left(\frac{y - 2}{8}\right)^2 = 1\).
Simplify the equation by multiplying both sides by \(64\) (since \(8^2 = 64\)) to obtain the Cartesian equation of the curve without the parameter \(t\).

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