Can anyone find the solution to this question

Find the gradient of f(x,y,z)equals=left parenthesis x squared plus y squared plus z squared right parenthesis superscript negative 1 divided by 2 baseline plus ln left parenthesis x right parenthesis x2+y2+z2−1/2+ln(xyz) at the point left parenthesis negative 2 comma 1 comma negative 2 right parenthesis(−2,1,−2).

In triangles abc and wxy, a=w and b=x which of the following must be true to prove abc=wxy by the aas theorem? a.ab=bc b.bc=xy c.ab=wx d.

State one method by which you can recognize a perfect square trinomial.