Question

Can somebody help me with parametric equations?

I do not have a TI-84 at the moment! Thanks!
1. Graph the following set of parametric equations on your calculator and select the matching graph.
2. Transform the given parametric equations into rectangular form. Then identify the conic.

Answer 1

Attachment 1 : Graph B

Attachment 2 : Option B

Explanation:

( 1 ) The equation x = t² - 3 is represented by exponential growth, ( t² ) so it's graph will be similar to the first graph, graph 1, in our options. Then again we have to consider the equation y = √t - 2, which will be similar to graph 4, but with a greater slope. This leaves us with a solution of graph b.

( 2 ) We have the following system of equations at hand here.

{ x = 5 cot(t), y = - 3csc(t) + 4 }

Now instead of isolating the t from either equation, let's isolate cot(t) and csc(t) --- Step #1,

x = 5 cot(t) ⇒ x - 5 = cot(t),

y = - 3csc(t) + 4 ⇒ y - 4 = - 3csc(t) ⇒ y - 4 / - 3 = csc(t)

Now let's square these two equations, adding them --- Step #2

We know that csc²θ - cot²θ = 1, so let's subtract the equations

( y - 4 / - 3 )² = (csc(t))²

- ( x - 5 / 1 )² = (cot(t))²

___________________

(y - 4)² / 9 - x² / 25 = 1

And as we are subtracting the two expressions, this is an example of a hyperbola. Therefore your solution is option b.