Question

If f(x) = x3 – 2x2, which expression is equivalent to f(i)?

Answer 1

–2 + i

–2 – i

2 + i

2 – I
My choices

Answer 2

\[i=\sqrt{-1}\\i^2=-1\\i^3=i^2i=-i\\i^4=(i^2)^2=(-1)^2=1\\\]

Answer 3

\[f(i)=i^3-2i^2=\\i^2i-2(-1)\]

Answer 4

can you go on ?

Answer 5

No, I honestly don't understand this section on complex number I've been working on the same quiz since 8:00

Answer 6

you can replace i^3 by -i
and
i^2=-1
put in function
let me see your work

Answer 7

where are you ?