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How to get the function ?

• To: mathgroup at smc.vnet.net
• Subject: [mg89330] How to get the function ?
• From: Joe <Joe.Varghese.John at gmail.com>
• Date: Fri, 6 Jun 2008 06:45:33 -0400 (EDT)

Hi All,

I am new to this group.  Hope this is the right one.

Assume a Circle with its bottom most point (-veY-axis from the center
meeting with circle) as the referance point.  That point is x=0, Y=0.

I know the X and Y values of a point on the circle from the referance
point.  Let that be (X1, Y1).
(Lets that point makes an angle of approx 30=B0 at the center with
respect to Y axis.)

My objective is to find the x and y values of a point which make a
specific angle, say 60=B0.

-----------------
Assume Theta1 is the Angle of (X1, Y1) and (0, 0) at the Center.
Assume Theta2 is the Angle of (X2, Y2) and (0, 0) at the Center.
Assume R is the Radius

Known values        > X1, Y1, Theta2

to find                   > Theta1, R

Result needed       > X2, Y2

------------------
X1        = R * Sin(Theta1)
R - Y1  = R * Cos(Theta1)

Solving this simutanious eq gives you R.

X2        = R * Sin(Theta2)
Y2       = R - ( R * Cos(Theta2) )
--------------------


Now the Qn is to rearrange the first two eq, so that I can find R
directly..
R = Fn( X1, Y1 )

what would be the function..............


Thanka a lot...
Joe.