Question

If x,y,z are real numbers, show that √−1×√−1×√−1=1

Answer 1

Step-by-step explanation:

distribute the brackets using FOIL( or any method you use)

(

5

−

2

i

)

(

5

+

2

i

)

=

25

+

10

i

−

10

i

−

4

i

2

[ this process is useful in complex numbers as the product produces a real number - the 2nd bracket is the complex conjugate of the 1st and vice-versa.]

[ note :

i

2

=

(

√

−

1

)

2

=

−

1

]

⇒

(

5

−

2

i

)

(

5

+

2

i

)

=

25

+

10

i

−

10

i

+

4

=

29

a real number

Answer 2

Step-by-step explanation:

I hope it is useful to you .