Question

f(x)=(x^2)(e^5x)
find f'(x) and f"(x).

why isnt the answer 2x*5e^5x?

Answer 1

product rule rules

Answer 2

for f'(x)

Answer 3

\[(fg)'=f'g+g'f\] is what you need

Answer 4

\[f(x)=x^2,f'(x)=2x. g(x)=e^{5x},g'(x)=5e^{5x}\] put it together in product rule

Answer 5

so it would be 2x^3 + 5e^25x^2

Answer 6

no

Answer 7

\[(fg)'=f'g+g'f\]

Answer 8

use the f, f', g, g' i wrote above and you should get it

Answer 9

i did

Answer 10

help?

Answer 11

your second term is wrong up there ^ Rewrite it

Answer 12

the e?

Answer 13

\[2x(e ^{5x})+x^2(5e ^{5x})\]

Answer 14

what about f"(x)

Answer 15

???

Answer 16

wait..sorry; im doing it.

Answer 17

ur fine

Answer 18

this problem appeared a lot simpler lol

Answer 19

lol; i havent done this in a while i forgot.. xD
My answer wasnt matching on with WOlfram Alpha thats why i got kinda confused..

Just use the product rule again..to differentiate or collect the like terms to differentiate easier.

Answer 20

ok you work it out mario

i will check where u r going wrong.. u just need to go step by step

Answer 21

hold on

Answer 22

would it be 2(e^5x) + (x^2)(5^2e^5x)???

Answer 23

\[\large e ^{5x}(2x+5x^2)\]
\[5e ^{5x}(2x+5x^2)+e ^{5x}(2+10x)\]
maybe..?

Answer 24

no

Answer 25

Whats the correct answer?

Answer 26

idk you tell me lol

Answer 27

lol, and you are saying no? :/

Answer 28

ok whats going on guyS?

Answer 29

is this too tough?

Answer 30

No; its easy.. i haven't done this in a long time and im so tired.
Akshay, you can do it!

Answer 31

my hw site tells me if its right or not but gives no answers

Answer 32

Probably you have to simplify it..

Answer 33

http://www.wolframalpha.com/input/?i=d%2Fdx+x%5E2+%28e%5E%285+x%29%29

Answer 34

lol; the answer is retarded on Wolfram Alpha..

Answer 35

cant u guys solve it? lol

Answer 36

I did..not sure though..too lazy to look through my old books, lol.

Answer 37

lol truthfully man i am waay toot tired from work :( i just wanna log off and sleep, but i feel sad leaving u in between :/

Answer 38

yeah i just wanna get this prob over with so i can eat and sleep

Answer 39

First derivative:
\[2x(e ^{5x})+x^2(5e ^{5x})\]
\[e ^{5x}(2x+x^2*5)\]
\[e^{5x}(2x+5x^2)\]
Second derivative, use the product rule:
\[5e ^{5x}(2x+5x^2)+e ^{5x}(x+10x)\]
Well, this is what i did; not sure though since im sooo tired.

Answer 40

its not right

Answer 41

You would probably have to simplify it if its an online thing...

Answer 42

to

Answer 43

or my answer is wrong..im too tried.

Answer 44

why is no one else helping? -_-

Answer 45

????????????

Answer 46

okay, can please restate problem? lots of stuff here, just want to know what the current problem is

Answer 47

i need f"(x)
(2nd derivative)

Answer 48

problem solved