ellipse ....... expert help req. !!!

an ellipse has major axis and minor axis lengths as 2a , 2b

let the foci be x1,y1 and x2,y2

and h,k be its center

and if it slides between co-ordinate axes such that it touches the x and y axis at all times

i)find the locus of one of the foci

ii)find the locus of the center

iii)the locus of the center id part of a circle ie an arc .... the angle subtended by thus ar at the origin is @

find cos@

9 Answers

3
iitimcomin ·

help!!!!! sum 1 ...

1
decoder ·

(2) let (h,k) be the centre
since the coordinate axis is touching the ellipse, origin is the point from which the two tangents are drawn.

now write general eq. (x-h)2/a2 +(y-k)2/b2=1

and then use T=0

sow homogenise T=0 with ellipse and put (coefficient of x2)+(coefficient of y2)=0
u will get the locus of centre

1
decoder ·

i have got also one elegant method for (2)

hint: since the tangents are perpendicular therefore the locus of point of their intersection is the director circle of ellipse .

3
iitimcomin ·

but dude .... (x-h)2/a2 +(y-k)2/b2=1 is the equation og an ellipse whose center is at h.k but whose major axis is parallel to the co-ordinate axis ...... but this is not the case here na

3
iitimcomin ·

some 1 help!!!!!!!!!!!!!!

19
Debotosh.. ·

locus of the centre is :x2 + y2 =a2 +b2

3
iitimcomin ·

the rem questions ???

19
Debotosh.. ·

we get only an arc of a circle while tracing the locus of the centre

3
iitimcomin ·

organic that is given in the question only that it forms an ark!!. ......

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