If f(x,y)=x2+92y2f(x,y) = x^2 + 92y^2f(x,y)=x2+92y2, what is nablaf\\nabla fnablaf?
langle2,184rangle\\langle 2, 184 \\ranglelangle2,184rangle
langle2x,92yrangle\\langle 2x, 92y \\ranglelangle2x,92yrangle
langlex,92yrangle\\langle x, 92y \\ranglelanglex,92yrangle
langle2x,184yrangle\\langle 2x, 184y \\ranglelangle2x,184yrangle