(1)设椭圆为x^2/a^2+y^2/b^2=1由题意得2b=6所以b=3将点(1 4)代入得1^2/a^2+4^2/3^2=1解得无解所以椭圆方程为y^2/a^2+x^2/b^2=1将点代入得4^2/a^2+1^2/3^2=1解得a^2=18所以y^2/18+x^2/9=1 (2)由题意得椭圆方程为x^2/a^2+y^2/b^2=1 a=6将点(3 3)代入得3^2/6^2+3^2/b^2=1解得b^2=12所以x^2/36+y^2/12=1