||'''Book'''|| Advanced Engineering Mathematics ||
 ||'''Author'''|| Erwin Kreyszig ||
 ||'''Edition'''|| 8th Edition ||

/* code_begins */

{{{
x = var('x')
y = var('y')

f(x,y) = 9*x^2 + 4*y^2


f(2,4), f(0.5, -3.25), f(sqrt(70), 1/sqrt(6)), }}}

/* code_ends */

 * '''Solution by''': 
  * ganesh, developer, space
  * bhanukiran, student, technical university of Delft
  * saransh, student, sobhit university