Find the product of the complex number (6i)(7i)?

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Answer 1 · 2017-11-13T14:48:00

See a solution process below:

First, rewrite the expression as:

#(6 xx 7)(i xx i) =>#

#42i^2#

The term #i = sqrt(-1)# Therefore we can substitute #sqrt(-1)# for #i# in the expression above and evaluate the expression as:

#42i^2# becomes:

#42(sqrt(-1))^2 =>#

#42 * -1 =>#

#-42#

Answer 2 · 2017-11-13T14:49:29

#-42#

#(6i)(7i)#
#=6*7*i^2#

By definition, #i^2 = -1#

Therefore,
#(6i)(7i)#
#=42*(-1)#
#=-42#

Answer 3 · 2017-11-13T14:52:43

-42

Remember

#color(blue)(i=sqrt(-1)#

So,

#rarr(7i)(6i)#

#rarr7*6*sqrt(-1)*sqrt(-1)#

#rarr42*-1#

#color(green)(rArr-42#

Hope this helps!!! ☺☻