find k if lim x->0 f(x)= f(0) and f(x)=(1-cosx/x^2, x<0 k, x=0 I*I/2X ,X>0

find k if lim x->0 f(x)= f(0) and f(x)=(1-cosx/x^2, x<0 k, x=0 I*I/2X ,X>0

About the author
Josephine