Complex Analysis/Essential Singularity/For the function f(z)=e^(1/z) , the point z=0 is ---?/TRB

TRB/Complex Analysis/Essential Singularity
Essential Singularity:
*If the Laurent series of f(z) contains an infinite number of negative power of (z-a),then z=a is called an Essential Singularity
*Limit does not exist.
*Different path different limit
*Principal part contains an infinite number of terms.
1.For the function f(z)=e^(1/z) , the point z=0 is ---?
2.If f(z)=e^z ,then f(z) has an essential singularity at?
3.The point z=-1 for the function
f(z)=(z−2)sin⁡(1/(z+1)) , is ---?
4.The function e^z,sinz,cosz then have an essential singularity at?

[@singaravelanc8663]

Thank so much sir isolated singularity and non isolated singularity please explain sir