- #1
TheKracken
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Homework Statement
Eliminate the parameter to find a description of the following circles or circular arc's in terms of x and y
and find the center and radius and indicate the positive orientation
x=cos(t) , y = 3sin(t) ; 0< t < pi/2 (should be less than or equal to)
Homework Equations
Not sure?
The Attempt at a Solution
When I find t = arccos(x) I then plug it in y=3 sin(t) and I result in
y= sqrt(9-x^2)
The book doesn't even give an answer for the equation part but it does tell me the origin, and radius and the
orientation but I figured you could rewrite my equation to y^2 + x^2 = 9 and that tell me the radius of 3 (sqrt (9) right?) then the orgin is 0,0 because nothing it being done to the x and y
but here is what trips me up, how do they know it is the lower half of a circle going counter clockwise? I mean it has to do something with the t's but I just don't see it.
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