1.

Find the eccentricity, centre, vertices, foci,minor axis, major axis, directrices and latus-rectum of theellipse `25 x^2+9y^2-150 x-90 y+225=0.`

Answer» `x^2/a^2+y^2/b^2=1`
`25x^2+9y^2-150x-90y+225=0`
`25(x^2-6x)+9(y^2-10y)+225=0`
`25(x^2-6x+9-9)+9(y^2-10y+25-25)+225=0`
`25(x-3)^2-225+9(y-5)^2-225+225=0`
`(25(x-3)^2)/225+(9(y-5))^2/225=1`
`(x-3)^2/9+(y-5)^2/25=1`
`x=X+3`
`y=Y+5`
`[x^2/3^2+Y^2/5^2=1]`
`e=sqrt(1-a^2/b^2)=sqrt(1-9/25)=4/5`
`x=0+3=3`
`y=Y+5=Y+5=5+5=10`
`y-5=5-5=0`
`(3,0),(3,10)`
`X=0,Y=pmbe`
`x=X+3`
`y=Y+5`
`=-4+5=1`
Equation of direction X and Y
`Y=pmb/e=pm5/(4/6)=pm25/4`
`y=Y+5=25/4+5=45/4`
`y=445/4,y=-5/4`
Major axis=`2b=2*5=10`
Minor axis=`2a=2*3=6`
Latus rectum=`(2a^2)/b=(2*9)/5=18/5`
Length of latus rectum.


Discussion

No Comment Found

Related InterviewSolutions