यदि `(a+ib) (c+id) (e+if) (g+ih) = A + iB` है तो दर्शाइए कि `(a^(2) +b^(2)) (c^(2) +d^(2)) (e^(2) +f^(2)) (g^(2) + h^(2)) = A^(2) + B^(2)`

Answer

`i^(2) = -1`