Problem 56 - Algebra and Trigonometry

Question

Find two different sets of parametric equations for each rectangular equation. \(y=x^{2}-3\)

Step-by-Step Solution

Answer

The two different sets of parametric equations for the given rectangular equation \(y=x^{2}-3\) are as follows: Set 1: \(x=t\), \(y=t^{2}-3\). Set 2: \(x= \sqrt{t}\), \(y=t-3\).

Step 1: Set 1 -Step 1: Set parameter as 't'

Set \(t\) equal to \(x\). This gives us our first parametric equation: \(x=t\).

Step 2: Set 1 -Step 2: Substitute for 'x' in 'y' equation

Substitute our parameter \(t\) for \(x\) in the \(y\) equation. This gives us our second parametric equation which is \(y=t^{2}-3\).

Step 3: Set 2 - Step 1: Set parameter as 't' in a differnt manner

This time, we get into the spirit of things and set \(t=x^2\). This will yield our first parametric equation for set 2: \(x= \sqrt{t}\).

Step 4: Set 2 - Step 2: Substitute for 'x' in 'y' equation

Substitute our parameter \(t\) for \(x^2\) in the \(y\) equation. This will yield our second parametric equation for set 2 which is: \(y=t-3\).

Key Concepts

rectangular equation

When we talk about rectangular equations, we are essentially dealing with equations that relate two variables, typically x and y. In most basic terms, a rectangular equation is just a standard algebraic equation in the Cartesian coordinate system. For example, the equation \( y = x^2 - 3 \) is a rectangular equation that defines a parabola opening upwards, shifted downward by three units.

Understanding rectangular equations is crucial because they provide a straightforward way to depict geometric shapes on a graph. These equations represent relationships between two variables without relying on a third variable or parameter.

• They help us visualize relationships in the two-dimensional plane.
• Are essential for understanding basics before delving into parametric forms.
• Form the foundation for converting into parametric or polar forms.

Each rectangular equation can often be converted into a parametric form, which gives us more flexibility in describing motion and time-based changes.

parameter substitution

Parameter substitution is the method of introducing a third variable, often called a parameter, to express the x and y variables in a set of equations. This process allows us to transform a rectangular equation into parametric equations.

When dealing with parametric equations, the idea is to express both the x and y coordinates in terms of another variable, typically denoted as 't'. This can sometimes lend itself to a more dynamic understanding of how x and y are related.

• In the given exercise, we start by setting \( t \) equal to \( x \). This makes \( x = t \).
• Substituting \( t \) into the equation for y gives us \( y = t^2 - 3 \).
• Alternatively, setting \( t = x^2 \) leads to a different parametric expression where \( x = \sqrt{t} \) and \( y = t - 3 \).

Parameter substitution can simplify complex calculations, especially when dealing with curves and motions, enabling us to map the trajectory of equations against time or another independent measure.

quadratic equations

Quadratic equations are pivotal in mathematics, featuring prominently in algebra and geometry. They are polynomial equations of degree two, generally in the form \( ax^2 + bx + c = 0 \).

For our specific rectangular equation, \( y = x^2 - 3 \), it's a clear example of a simple quadratic equation where \( a = 1 \), \( b = 0 \), and \( c = -3 \). This describes a parabola on a graph. The vertex of this particular parabola is at \( (0, -3) \), and it opens upwards.

• Understanding the graph of a quadratic helps in visualizing the equation’s geometric properties.
• The vertex form of a quadratic can make it easier to spot transformations and translations.
• Quadratics are used in numerous applications, from physics to economics, due to their predictable properties.

The beauty of quadratic equations lies in their symmetry and their ability to model various real-life scenarios, from projectile motion to calculating profits and losses.