| a b |^2+| a b |^2=144 and | a |=4 , then | b | is equal to

Step-by-step solution

Given, | a b |^2+| a b |^2=144 and | a |=4 aligned & | a |^2| b |^2 ^2 +| a | b |^2 ^2 =144 & | a |^2| b |^2 [ ^2 + ^2 ]=144 aligned array ll & (4)^2 |b|^2=144 & |b|^2= 144 16 =9 & |b|=3 array