My Math Forum  

Go Back   My Math Forum > High School Math Forum > Algebra

Algebra Pre-Algebra and Basic Algebra Math Forum


Reply
 
LinkBack Thread Tools Display Modes
February 21st, 2009, 02:00 PM   #1
Newbie
 
Joined: Feb 2009

Posts: 2
Thanks: 0

Solve angle and radius of oval

I have a formula:
X = (radius*n+f)*sin(a)
Y = radius*cos(a)

Which, when plotted, gives me a very flat oval when the radius is
small moving out to a circle and then to a tall oval. (eg. n = 0.55,
f=195, becomes a circle when the radius is approx 433.333)

Now what I need is to be able to reverse the formula. I have the
values for X, Y, n, f. I need to calculate rad and a.


If I re-arrange the formula to :

X = ((Y/cos(a))*n+f)*sin(a)

or

X = Y*n*sin(a)/cos(a) + f*sin(a)

All values are known except a.
But how do I re-write this so I have a formula
a = .........
pmoor is offline  
 
February 21st, 2009, 04:55 PM   #2
Global Moderator
 
Joined: Dec 2006

Posts: 20,978
Thanks: 2229

You can use sina + cosa = 1 to eliminate a, and then solve the resulting quartic equation for the radius.
skipjack is offline  
Reply

  My Math Forum > High School Math Forum > Algebra

Tags
angle, oval, radius, solve



Thread Tools
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Radius angle from 2 points coderplus Algebra 9 August 4th, 2012 11:31 AM
Ellipse radius at specific angle? keijojo Algebra 8 May 15th, 2012 12:08 PM
how Do I calculate the oval shape icm63 Algebra 12 January 17th, 2012 12:48 PM
Question dealing with a spiral shape with angle and radius i_am_cuul Algebra 1 April 23rd, 2010 08:50 PM
Rotated oval graphing equation help. SquirrellyMcGee Algebra 0 December 31st, 2009 12:12 PM





Copyright © 2019 My Math Forum. All rights reserved.