Question

Use differentiation to show that the given sequence is strictly increasing or strictly decreasing.

Answer 1

for my answer i had originally entered 4/(3n+4)^2 but it marked me as incorrect. not sure what im doing wrong

Answer 2

if the derivative is always +, then its strictly increasing

if its always - then well .... decreasing

Answer 3

\[n(3n+4)^{-1}\]
\[(3n+4)^{-1}-3n(3n+4)^{-2}\]
\[[(3n+4)-3n]~(3n+4)^{-2}\]
\[\frac{4}{(...)^2}\]
since (..)^2 is always + and 4 is always +, this is never negative, never decreasing

Answer 4

its asking for f(x) not f(n) ... its a continuous represenation of a discrete function

Answer 5

so you should be able to change n to x and it shold be good

Answer 6

why didn't i see that!! thank you so much :)

Answer 7

ill try it out !