1 - If a graph represented by f(x,y)=0 is symmetric with respect to x-axis, we should have f(x,y)=f(x,-y).
Here, in 6x^2=y-1, we have f(x,y)=6x^2-y+1=0 and f(x,-y)=6x^2-(-y)+1=6x^2+y+1 and hence
f(x,y)!=f(x,-y) and hence it is **not symmetric w.r.t. x-axis.
2 - If a graph represented by f(x,y)=0 is symmetric with respect to y-axis, we should have f(x,y)=f(-x,y).
In 6x^2=y-1, we have f(-x,y)=6(-x)^2-y+1=6x^2-y+1 and hence
f(x,y)=f(-x,y) and hence it is symmetric w.r.t. y-axis.
3 - If a graph represented by f(x,y)=0 is symmetric with respect to line y=x, we should have f(x,y)=f(y,x).
In 6x^2=y-1, we have f(y,x)=6y^2-x+1 and hence
f(x,y)!=f(y,x) and hence it is not symmetric w.r.t. line y=x.
4 - If a graph represented by f(x,y)=0 is symmetric with respect to line y=-x, we should have f(x,y)=f(-y,-x).
In 6x^2=y-1, we have f(-y,-x)=6(-y)^2-(-x)+1=6y^2+x+1 and hence
f(x,y)!=f(-y,-x) and hence it is not symmetric w.r.t. line y=-x.
graph{(6x^2-y+1)(x-y)(x+y)=0 [-5.394, 4.606, -0.64, 4.36]}