Posted by Ttt on Thursday, October 27, 2011 at 3:18am.
Classify the conic section
4x^2+5y^216x30y+41=0 as a circle, ellipse, hyperbola, or parabola?

Math  drwls, Thursday, October 27, 2011 at 4:20am
Ellipse
4(x^2 4x +4) + 5(y^2 6y +9) = 41 + 16 + 45
= 20
= 4(x2)^2 + 5(y3)^2
(x2)^2/5 + (y3)^2/4 = 1 
Math  Anonymous, Thursday, October 27, 2011 at 10:07am
The sum of 16terms of an A.P IS 504,while the sum of its 9terms is 126. Find the sum of its 30terms