Question

If F(x)=x^3-2x^2, which expression is equivalent to f(I) -2+i,-2-i,2+i,2-i

Answer 1

Hello from MrBillDoesMath!

Answer:

2 - i

Discussion:

Evaluate F(x) = x^3 - 2 x^2 when x = i.

i^2 = -1 for i^3 = i ( i^2) = i (-1) = -i

So F(i) =  (i)^3 - 2 (i)^2                      

          =   -i     - 2(-1)

          = -i      +  2

          =  2      -  i

which is the last answer shown

Thank you,

MrB