Answer:
[tex]( \frac{x}{3} ) {}^{2} + ( \frac{y}{3}) {}^{2} = 1[/tex]
or x² +y²= 9
Step-by-step explanation:
In Cartesian form, the equation is expressed only in terms of y and x.
x= -3sin(t) -----(1)
y= 3cos(t) -----(2)
I've written x instead of x(t) as in the later part of the working, we will be having an equation of only x and y, thus x will no longer be a function of t. This applies to equation 2, where I have replaced y(t) with y.
Relating sine to cosine:
sin²(t) +cos²(t)= 1
[sin(t)]² +[cos(t)]²= 1 -----(3)
From (1):
[tex] \frac{x}{ - 3} = \sin(t) [/tex]
[tex] \sin(t) = - \frac{x}{3} [/tex] -----(3)
From (2):
[tex] \frac{y}{3} = \cos(t) [/tex]
[tex] \cos(t) = \frac{y}{3} [/tex] -----(4)
Substitute (4) &(5) into (3):
[tex]( - \frac{x}{3} )^{2} + ( \frac{y}{3}) {}^{2} = 1[/tex]
[tex]( \frac{x}{3} ) {}^{2} + ( \frac{y}{3} ) {}^{2} = 1[/tex]
The steps below are optional as the above is already considered to be the Cartesian form.
[tex] \frac{ {x}^{2} }{9} + \frac{y {}^{2} }{9} = 1[/tex]
Multiplying both sides by 9:
x² +y²= 9
