Question

Find parametric equation and parametric interval for the motion of a particle starting at (4,0) and tracing half top of the circle x^2+y^2=16 six times.

Answer 1

i got it

Answer 2

thnx for looking though

Answer 3

I got \(x=4\cos{t}\), and \(y=4|\sin{t}|\). Is that what you got?

Answer 4

yeah

Answer 5

Thanks!

Answer 6

:)

Answer 7

thanks!

Answer 8

Polar Coordinates formulas
\[x=rCos(t)\]
\[y=rSin(t)\]

Since the rardius of the given circle equation is 4, r=4
\[x=4Cos(t)\]
\[y=4Sin(t)\]
and Bingo. Notice that since the tracing is from the x axis going counter-clockwise no change need be made....no absolute values, flip-flopping trig functions or any of the like.

Answer 9

thanx, but i think for y i need absolute value because it is just tracing upper half(where y is always positive)