If the graph of the function fx=ax-1xnax+1 is symmetrical about the y-axis, then n can be

fx=ax-1xnax+1      fx  issymmetricalabouty-axis.  Thus,          fx=f-xor   ax-1xnax+1=ax-1-xna-x+1or    ax-1xnax+1=1-ax-xn1+a-xor  xn=--xnHence, the value of n which satisfies this relation is -13