#Calculate logs
123 messages · Page 1 of 1 (latest)
<@&286206848099549185>
<@&286206848099549185>
do a thing
use a^2 - b^2 = a+b)*(a-b)
and write 2 log 5 as log 25
so the ques becomes
3 log 10 * [ 3 log 2/5 ] * [ 2 log 10 ] / log (0.4)
log 0.4 = log 2 / 5
so therefore the sol is 18 * ( log 10 ) ^2
and if you have log with base 10 as defined
then its just 18
hmmm
thanks for the help and the explanation
your welcome
also im confused on finding the domain for fog
wait
bro
fog = -1 / x^2
domain are set of input values
so x^2 ≠ 0
so x ≠ 0
so domain = R - {0}
it says its wrong
try writing x≠0
btw what software is it
free?
yea thats what i did
no
...
then not for me lol
i cant understand where we r backing
-∞ < x < 0
0 < x < ∞
try this
its wrong
i m not doing it anymore
wassup gojo
what you need
need to find domain for fog (x)
well f o g (x) domain depends on the domain of g and f
yea
g is 1<= x<=1
so f o g = f(g(x))
Yep
So we are plugging in values between [-1, 1] in g
and get values out between f([0,1])
Now since f must not be 1
Okay
we actually should make [0,1) exclude the 1
and the one is caused by x = 1 and x = -1
so those values of x are not part of the domain
also f o g = f(g(x)) = -1/x² so is there another value that is not allowed?
hm it says its wrong
we are not finished
what did you even type
g(x) domain was [-1;1]
now with f(g(x)) it should be (-1; 0) U (0;1)
-1 < x<1, and 0<x<1?
or -1 < x < 0 U 0 < x < 1
is that it
-1 < x< 0, 0 < x<1
yes
do you even listen what i wrote or do you just want straight solutions?
-1 < x< 0 or 0 < x<1
final
try [-1;1]\{0}
The problem is you are trying find the domain just by looking at f(g(x)) but you have to consider the previous domains too meaning composite functions are much more conplicated
I made a slight mistake when I explained, the -1 and 1 are part of the domain the 0 is not
Oh ok thanks
It still says incorrect
then i m done
i m just a student
thats what i did
R - {0}
Can you send a picture?
-1 <= x < 0 or 0 < x <= 1
But it cannot be R if g(x) domain is |x| <= 1
doesnt it independent of g(x)
@tall oyster
Thats my point it does depend
how
"Note that the domain of f composed with g is the set of all x such that x is in the domain of g and
g(x) is in the domain of f(x)"
ok
so while writing fog
we write f { g(x) }
so with value not in g(x) it will become undefined
thanks
Basically find all values of x such that g(x) is in the domain of f(x) with respect to the domain of g(x)
yeah
so we need the common domian btw f(x) and g(x)
yeah kinda
thanks man
$f o g = f(g(x)) = \frac{1}{g^2(x) - 1}\$
So that would mean basically:
$\ g(x) < 1$ or $g(x) > 1$ but we can leave $g(x) > 1$ out since the range of g(x) is between 0 and 1
That was the idea
adonhs
yea this was correct thanks
Well then you typed somethin wrong or they only accept this kind of notation