# if x=3sin(delta) and y=3 cos(delta) -2, eliminate delta to find an equation relating x and y

*print*Print*list*Cite

### 1 Answer

Given, `x=3sindelta` , `y=(3cosdelta-2)`

square and add both sides of the two equations,

`x^2+y^2=9sin^2delta+9cos^2delta-2*3cosdelta*2+4`

`=9(sin^2delta+cos^2delta)-4(3cosdelta-2)+4-8`

`=9-4y-4`

`=5-4y`

add 4y+4 to bothe sides of the equation,

`rArr x^2+y^2+4y+4=9`

`rArr x^2+(y+2)^2=9`

`rArr x^2/3^2+(y+2)^2/3^2=1`

=>answer