If f (x) `= cos ( log _e x ) ` then
` f(x) . f(y) - (1)/(2) [f(y/x ) + f (xy)]` has the value

If f(x,y,z) = sin (xy) + cos(xz) , then f_("xx") is

If f(x)=(log)_e((x^2+e)/(x^2+1)) , then the range of f(x)

If f(x)=log_(e)(log_(e)x)/log_(e)x then f'(x) at x = e is

Iff(x)=sin(logx) then f(xy)+f( y x ​ )−2f(x)cos(logy) is equal to

If f(x) =|log_(e)|x||, then f'(x) equals

If f(x,y,z) =xy + yz + zx, then f_(x) - f_(z) is equal to

If f is a function satisfying f (x +y) = f(x) f(y) for all x, y in N such that f(1) = 3 and sum _(x=1)^nf(x)=120 , find the value of n.

If f(x,y) = 2x^(2) - 3xy + 5y^(2) +7 , then f(0,0) and f(1,1) is