/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 24 The given curve is part of the g... [FREE SOLUTION] | 91Ó°ÊÓ

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The given curve is part of the graph of an equation in \(x\) and \(y .\) Find the equation by eliminating the parameter. $$x=8 t^{3}-4 t^{2}+3, \quad y=2 t-4, \quad \text { any real number } t$$

Short Answer

Expert verified
Question: Eliminate the parameter "t" in the parametric equations \(x = 8t^3 - 4t^2 + 3\) and \(y = 2t - 4\) to find the equation in \(x\) and \(y\). Answer: The equation, after eliminating the parameter "t", is \(x = y^3 + 11y^2 + 40y + 51\).

Step by step solution

01

Solve one of the parametric equations for t

Since the equation \(y = 2t - 4\) is much simpler, we can solve it for \(t\) and find: $$t = \frac{y + 4}{2}$$
02

Substitute the expression for t into the other parametric equation

Now that we have an expression for \(t\) in terms of \(y\), we can substitute it into the parametric equation for \(x\) to eliminate \(t\). Substituting \((y + 4)/2\) for \(t\) in the parametric equation for \(x\), we get: $$x = 8\left(\frac{y + 4}{2}\right)^{3} - 4\left(\frac{y + 4}{2}\right)^{2} + 3$$
03

Simplify the equation

To simplify, multiply the terms inside the parenthesis first, then expand the powers, and finally combine the terms. $$x = 8\left(\frac{1}{8}(y + 4)^{3}\right) - 4\left(\frac{1}{4}(y + 4)^{2}\right) + 3$$ $$x = (y + 4)^{3} - (y + 4)^{2} + 3$$
04

Expand the equation

Now, we need to expand the equation and simplify it: $$x = (y^3 + 12y^2 + 48y + 64) - (y^2 + 8y + 16) + 3$$ $$x = y^3 + 12y^2 + 48y + 64 - y^2 - 8y - 16 + 3$$ $$x = y^3 + 11y^2 + 40y + 51$$
05

Final Answer

So, the equation that describes the curve, after eliminating the parameter \(t\), is: $$x = y^3 + 11y^2 + 40y + 51$$

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Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Parametric Equations
Parametric equations allow us to represent curves in the coordinate plane by using a third variable, commonly denoted as 't', which serves as a parameter. In the exercise, we're given two parametric equations where the coordinates \(x\) and \(y\) of any point on the curve are expressed in terms of \(t\): \[x=8 t^{3}-4 t^{2}+3\] and \[y=2 t-4\]. These equations define a set of points \( (x, y) \) for each real number value of \(t\), and together they trace out a curve as \(t\) varies.

The advantage of parametric equations is their ability to describe a wide variety of curves, including those that cannot be represented by a single function of \(x\) or \(y\). They are particularly useful in applications involving motion, where \(t\) can represent time, allowing us to track the position of a moving point over that time. Additionally, they are capable of tracing curves that loop back on themselves, a feat that is impossible for functions defined explicitly as \(y\) in terms of \(x\) or vice versa.

In the context of the exercise, the purpose is to transform the given parametric equations into a single equation involving only \(x\) and \(y\) by eliminating the parameter \(t\). This non-parametric form is often easier to analyze and graph without having to consider a range of \(t\) values.
Algebraic Manipulation
Algebraic manipulation is a vital skill in mathematics used to rearrange, simplify, and solve equations. In the given solution steps, this set of techniques is used to eliminate the parameter \(t\) and find an equation purely in terms of \(x\) and \(y\).

Firstly, we must isolate \(t\) in one of the given parametric equations, usually choosing the simpler one to manipulate, as in \[t = \frac{y + 4}{2}\]. Next, this expression for \(t\) is substituted back into the other equation involving \(x\), resulting in an equation with \(x\) in terms of \(y\), effectively 'eliminating' \(t\) from the equation: \[x = 8\left(\frac{y + 4}{2}\right)^{3} - 4\left(\frac{y + 4}{2}\right)^{2} + 3\].

Following substitution, algebraic manipulation involves expanding powers, simplifying terms, and combining like terms, which can include distributing exponents and applying basic arithmetic operations. These methods lead to a clearer equation that is easier to work with when plotting graphs or evaluating specific points on the curve.
Equation of Curve
An equation of a curve is a mathematical expression that describes the relationship between two variables, typically \(x\) and \(y\), in such a way that each point satisfying the equation lies on the curve. In the case of parametric equations, converting them to a single algebraic equation involves eliminating the parameter, as we did in the earlier steps.

After algebraic manipulation, we arrive at an explicit form of the equation for \(x\) as a function of \(y\): \[ x = y^3 + 11y^2 + 40y + 51 \]. This form of the equation is much more convenient for several mathematical operations, including finding points of intersection with other curves, calculating tangents, or simply graphing the curve.

It is important to understand that not all parametric curves can be easily translated into a simple equation in \(x\) and \(y\) due to their complexity. However, the example provided demonstrates how, with careful algebraic manipulation, it's often possible to find such an equation, making the study of the curve's properties and behavior more accessible.

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