Question

What is the derivative of the complex (iz^3+3z^2)^3 at 2i

Answer 1

I did chain rule and got 3(iz^3+3z^2)(3iz^2+6z)

Answer 2

Just wondering what do I do with the 'at 2i'?

Answer 3

evaluate the derivative at x = 2i...

Answer 4

so I replace all the z with z=x+yi?

Answer 5

but then I have y's... what do I do with those

Answer 6

No, you replace z with 2i, sorry, I typed x, should have typed z

Answer 7

oh okay got it thank you!

Answer 8

Not entirely convinced by your derivative, however...

Answer 9

You should have a power of two applied to one of the sets of parentheses, as you started out with a ^3...