show that k(x)= (5x^3) + (5/x^3) - x- (1/x)

Answer 1

^ sorry didn't finish: show that k(x)= k(1/x)

Answer 2

let me rewrite k(x)

k(x) = 5(x^3) + 5(1/x^3) - x/1 - 1/x

it should be intuitively obvious that
k(x) = k(1/x)

Answer 3

yea i realize that but the question says "show" that they equal each other. im thinking possibly by some sort of identity or something.

Answer 4

sub 1/x for x

k(1/x) = 5(1/x^3) + 5/(1/x^3) - 1/x - 1/(1/x)
= 5/x^3 + 5x^3 - 1/x - x

= the original k(x) , just the order of writing down the terms has changed.

Answer 5

ohh i see duh!! lol thanks =)