1 1 vote Let $x$ and $y$ be real numbers satisfying $9x^2+16y^2=1$. Then $(x+y)$ is maximum when $y=9x/16$ $y=-9x/16$ $y=4x/3$ $y=-4x/3$ Others isi2016-mma differentiation non-gatecse + – go_editor 415 views answer comment Share Follow Print 0 reply Please log in or register to add a comment.