Question

How do I graph an ellipse on a $\text{TI-84}$?

Answer 1

In this question we will see as to how to make or draw an ellipse on a $\text{TI-84}$ calculator, which is a scientific calculator. We will first see the general form of an ellipse and see all the variables present in the general form. And then see the steps as to how to draw an ellipse on a $\text{TI-84}$ calculator using it inbuilt graphing app.

Complete step by step solution:
We know that there are two types of ellipses, a vertical ellipse and a horizontal ellipse. A vertical ellipse in an ellipse whose major axis is in the $y$-axis and the minor axis in the $x$-axis whereas a horizontal ellipse has its major axis in the $x$-axis and the minor axis is in the $y$-axis.
The general equation of a horizontal ellipse is $\dfrac{{{\left( x-h \right)}^{2}}}{{{a}^{2}}}+\dfrac{{{\left( y-k \right)}^{2}}}{{{b}^{2}}}=1$ and the general equation of a vertical ellipse is $\dfrac{{{\left( x-h \right)}^{2}}}{{{b}^{2}}}+\dfrac{{{\left( y-k \right)}^{2}}}{{{a}^{2}}}=1$ , where $\left( h,k \right)$ is the coordinate of the center of the circle, $a$ is the length of the vertex which is the horizontal length of the ellipse and $b$ is the length of the co-vertex which is the vertical length.
The steps to draw an ellipse on a $\text{TI-84}$ calculator are:
$1)$ press the $\left[ \text{apps} \right]$ button and scroll down to select conics and press $\left[ \text{enter} \right]$.
$2)$ inside the conic’s menu scroll down to select ellipse and press $\left[ \text{enter} \right]$.
$3)$ inside the ellipse menu, select either horizontal ellipse or vertical ellipse and press $\left[ \text{enter} \right]$.
$4)$ enter the values of the variables $a,b,h,k$ by using the down arrow key and press the $\left[ \text{graph} \right]$ button to get the required ellipse.

Note: It is to be remembered that this method is unique to the $\text{TI-84}$ calculator and the steps on calculators other than this may vary. It is to be remembered that the graph generated will be unlabeled therefore to check the coordinates press the $\left[ \text{trace} \right]$ button and use the arrow keys to trace along the ellipse to see the coordinates.