Question

If i is the imaginary unit such that sqrt(-1) = i, then (7i)2 = ?

Answer 1

(7i)^2

Answer 2

please help me

Answer 3

See it as 7 multiplied by i all squared
If you prefer xy all squared which is x^2y^2

Therefore 7i all squared is 7^2i^2 which is 49 x -1 - -49

Answer 4

-49

Answer 5

-1^2=-1?

Answer 6

no of course not. it is
\[i^2=-1\] because
\[i=\sqrt{-1}\]

Answer 7

no i^2 = -1