Question

Evaluate the following limit:
lim x->0 sin(x) cos (x)/x

Answer 1

\[\lim_{x \rightarrow 0}sinxcosx/x=\lim_{x \rightarrow 0}sinx/x*\lim_{x \rightarrow 0}\cos(x)\]

both limits are 1. So the whole limit is 1

Answer 2

cos x/ x = 1?

Answer 3

sinx/x->1
cosx is left over but also goes to 1
both as x->0

Answer 4

i got DNE

Answer 5

no the limit exists, it is 1. cos(x) goes to 1 and sinx/x goes to 1 as well

Answer 6

because cos x / x = 1/0... no?

Answer 7

lol can you not write the function as sinx/x *cosx?

Answer 8

you aren't plugging in 0 though it's a limit

Answer 9

there are limits that have a division by 0 and still exist it is about infinitesimal behavior

Answer 10

no i wrote sinx / x * cosx / x

Answer 11

it is not x^2 on the bottom

Answer 12

(5*6)/(5)=6
but by what you say we can do or suppose to do
5/5*6/5=6/5

Answer 13

i mean (5*6)/5=5/5*6=1*6=6
and you say (5*6)/5=5/5*6/5=6/5
is that what you are saying this second line right here?

Answer 14

i seperate the fraction

Answer 15

i think you are thinking about addition on fractions
(a+b)/c=a/c+b/c

Answer 16

sorry guys the lag go the best of me

Answer 17

no i mean the 2nd line what you di

Answer 18

did*

Answer 19

you can't do (5*6)/5=5/5*6/5
but you do (5*6)/5=5/5*6 or 5/6*5=6

Answer 20

yes the 2nd line

Answer 21

yes the 2nd line

Answer 22

so we can write sinx/x*cosx?

Answer 23

no sin x/x * cox x /x

Answer 24

but you just said we can't do (5*6)/5=5/5*6/5

Answer 25

(sinx*cosx)/x=sinx/x * cosx

Answer 26

or =cosx/x * sinx ( it does us no good to write it like this though)

Answer 27

so how do i work it? i am confused

Answer 28

write (sinx*cosx)/x=sinx/x*cosx
where does sinx/x go to as x gets closer to 1?

Answer 29

as x gets closer to 0?*

Answer 30

do you know how to use latex here because i dont understand what you typed

Answer 31

so the answer is 1 i dont undertstand why it cant be done the way i did it i understand what you typed

Answer 32

so you still don't understand why we can't do:
\[\frac{\sin(x)\cos(x)}{x}=\frac{\sin(x)}{x}\frac{\cos(x)}{x}?\]

Answer 33

we don't have x^2 on bottom? we only have x

Answer 34

yes
\\

Answer 35

\[\frac{5*6}{5}\neq \frac{5}{5}*\frac{6}{5}\]

Answer 36

do you agree with this statement?

Answer 37

ok...

Answer 38

\[\frac{5*6}{5}=\frac{5}{5}*6=6\]

Answer 39

\[\lim_{x \rightarrow 0} \frac{\sin(x)\cos(x)}{x}=\lim_{x \rightarrow 0}\frac{\sin(x)}{x}*\cos(x)\]

Answer 40

k

Answer 41

\[=\lim_{x \rightarrow 0}\frac{\sin(x)}{x}*\lim_{x \rightarrow 0}\cos(x)=1*1=1\]

Answer 42

i guess i gotta recheck my fractions thank you so much i have 1 more question if your not busy can you help me with that please

Answer 43

i gotta pee i might return

Answer 44

lol ok THANK YOU SO MUCH