This is about ellipses:
If a problem gives you two foci points and the length of a spring, how do you find the equation and the vertices of the ellipse?
2 answers
Also, if you have only the equation of an ellipse and the foci points, how do you find the length of the string?
spring? or string?
Pretty easy. Put the string at each foci up to the top of the semimajor axis.
LenghString^2=)2*focidistance )^2+semimajoraxis^2
from that, find the semimajor azis.
Next, put the string horizontal to the major axis.
Length string=2semimaforaxis+majoraxis
solve for major axis length.
Pretty easy. Put the string at each foci up to the top of the semimajor axis.
LenghString^2=)2*focidistance )^2+semimajoraxis^2
from that, find the semimajor azis.
Next, put the string horizontal to the major axis.
Length string=2semimaforaxis+majoraxis
solve for major axis length.