Question

How do I eliminate the parameter t for x=cos(t)-sin(t), y=cos(t)+sin(t)?

Answer 1

have you tried to see what x^2+y^2 gives you ?

Answer 2

yes it gives cos^2(t)-2cos(t)sin(t)+sin^2(t)+cos^2(t)+2cos(t)sin(t)+sin^2(t)
which gives 2cos^2(t)+2sin^2(t)

Answer 3

what is cos^2(t)+sin^2(t)=?

Answer 4

thinking Pythagorean identity

Answer 5

I got x^2+y^2 is 2

Answer 6

cool stuff

Answer 7

you have eliminated the variable t

Answer 8

yes, i see

Answer 9

how do i graph the parametric equation?
I'm getting a nonsense plot points

Answer 10

have you ever graph circles in the past?

Answer 11

not really

Answer 12

\[d=\sqrt{(x_1-x_2)^2+(y_1-y_2)^2}\]
this is the distance between (x1,y1) and (x2,y2)
do you know this?

Answer 13

yes

Answer 14

say I drew a perfect circle here
and we have that any line segment that I draw from the center to a point on the circle are of equal distance

Answer 15

it is called a radius by the way
let's say the distance between (h,k) and call that point on the circle I just drew (x,y)