Question

if x2+y2+6xy, prove that 2log(x+y)=logx+logy+3log2

Answer 1

=> log(x+y)²==log(2³xy)
=> x²+2xy+y²==8xy          //given x²+y²=6xy...put this in LHS
=>6xy+2xy=8xy≡8xy
∴ RHS=LHS  Proved!