document.write( "Question 821906: find the foci of the conic section represented by the following equation 4x^2+25y^2=100 \n" ); document.write( "
Algebra.Com's Answer #494494 by DrBeeee(684)\"\" \"About 
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Given
\n" ); document.write( "(1) 4x^2 + 25y^2 = 100
\n" ); document.write( "Divide through by 100 to get
\n" ); document.write( "(2) (4/100)x^2 + (25/100)y^2 = 1 or
\n" ); document.write( "(3) (x^2)/25 + (y^2)/4 = 1 or
\n" ); document.write( "(4) (x/5)^2 + (y/2)^2 = 1 which is the standard form of the ellipse
\n" ); document.write( "(5) (x/a)^2 + (y/b)^2 = 1 where
\n" ); document.write( "(6) a = 5 and
\n" ); document.write( "(7) b = 2
\n" ); document.write( "The distance from the center (0,0) in x,y coordinates to either focal point is given by
\n" ); document.write( "(8) f = sqrt(a^2 - b^2) or
\n" ); document.write( "(9) f = sqrt(25-4) or
\n" ); document.write( "(10) f = sqrt(21)
\n" ); document.write( "Answer: The foci are at (x,y) = (+sqrt(21),0) and (-sqrt(21),0) or
\n" ); document.write( "approximately (4.58,0) and (-4.58,0). \n" ); document.write( "
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