If f(x) = x3 – 2x2, which expression is equivalent to f(i)?
a) –2 + i
b) –2 – i
c) 2 + i
d) 2 – i

Answer

d) 2 – i

Explanation

f(x) = x³ – 2x²

When x = i, we proceed as follows.

Note: i =

          i² =(√-1)(√-1) =  -1

          i³ = (√-1)(√-1)(√-1) = -1(√-1) = -1i = -i

f(x) = x³ – 2x²

f(i) = i³ – 2i²

     = -i – 2(-1)

     = -i + 2

      = 2 – i

the required function is .

step-by-step explanation:

from the given table it is noticed that the graph passing through (-3,7), (0,4), (3,1) and (8,-4).

it is a linear function because the value of y is decrease by one as the value of x increase by 1.

the slope of the function is

the slope of the function is -1 and the y-intercept is 4.

the slope intercept form is

where, m is slope and b is y-intercept.

therefore the required function is . the graph of this function is shown below.