Question...

ƒ(x,y) = (4x²) / (1x²+5y²)

lim (x,y)→(0,0)

What is the limit along the liney=mx

My Attempt

The function then becomes...

ƒ(x,mx) = (4x²) / (1x²+5mx²)

lim (x,mx)→(0,0)

I thought the answer was then as easy as dropping all the variables and seeing that approaching the origin the function is closest to 4/6, but this is incorrect.

What am I not understanding?