Question

Write, in parametric form, the equation of the \(y\) axis.

Short answer

The parametric form of the equation for the y-axis is \( x(t) = 0 \) and \( y(t) = t \).

Step-by-step solution

Understand the Concept of Parametric Equations

In parametric equations, points on a curve are represented as functions of a parameter, usually denoted by 't'. For a curve, this means expressing the coordinates (x, y) as (x(t), y(t)).

Identify the Characteristics of the y-axis

The y-axis consists of all points where the x-coordinate is always 0, regardless of the y-coordinate. Therefore, x is always 0.

Define x(t) and y(t)

Since the x-coordinate is always 0, we can write: x(t) = 0. The y-coordinate can be any real number, so we can let y(t) = t, where t is any real number.

Write the Parametric Equations

Combine the expressions from the previous step to write the parametric form of the y-axis: \( x(t) = 0 \)\( y(t) = t \)where t is a parameter that can take any real value.

Key concepts

y-axis

The y-axis is an essential concept in the coordinate system. It is the vertical line that runs through the origin, where the x-coordinate is always zero, no matter what the y-coordinate is. This means every point on the y-axis has coordinates of the form (0, y). Understanding the y-axis is crucial because it helps you visualize how vertical lines behave in graphs.
For example, the point (0, 5) lies on the y-axis, as well as the point (0, -3). These points stretch infinitely in the positive and negative directions along the y-axis.

parametric form

In mathematics, parametric equations are a way to express coordinates using a parameter, denoted as 't'. This is different from the standard form where you have equations directly connecting x and y. Instead, parametric form allows for (x, y) to be expressed as functions of 't'.
For the y-axis example, the equations are:
\[x(t) = 0\]
\[y(t) = t\]
where t is any real number. This setup allows us to generate all the points on the y-axis through different values of 't'. By varying 't', we cover every possible point where x is zero and y can take any value.

coordinate system

The coordinate system, specifically the Cartesian coordinate system, consists of two perpendicular axes: the x-axis (horizontal) and the y-axis (vertical). These two axes intersect at a point called the origin, defined as (0, 0).
This system allows us to define any point in a plane using an ordered pair of numbers (x, y). For instance:

• (2, 3) means moving 2 units along the x-axis and 3 units along the y-axis.
• (-1, -4) indicates moving 1 unit left on the x-axis and 4 units down the y-axis.

The coordinate system is a powerful tool for graphing equations and visualizing more complex mathematical concepts.

real numbers

Real numbers are the set of all numbers that can be found on the number line. This includes both rational numbers (like 2, 1/2, and -3) and irrational numbers (like √2 and π).
When working with parametric equations, especially for the y-axis, the parameter 't' can take on any real number value. This means:

• For t = 0, the point is (0, 0).
• For t = 5, the point is (0, 5).
• For t = -3, the point is (0, -3).

By allowing 't' to be any real number, the parametric equations cover every possible point along the y-axis.