Question

OMFG HELP PLZ I COULDN'T FIND WHAT'S WRONG, VERIFIED 50 TIMES AND STILL TELLS ME THERE'S AN ERROR :(((((((

http://puu.sh/11muU

Answer 1

one of them is wrong, can anyone find it? :S

Answer 2

i got -11 for the first one. let me move to the second

Answer 3

ye!!!!!

Answer 4

got -3/2 for second one

Answer 5

YEEE!!!

Answer 6

-5/16 for the third one

Answer 7

YES!

Answer 8

Are you sure the third isn't supposed to be -5/4?
I'll try it again.

Answer 9

and finally 15 for the last one
there are two possible problems i can see

Answer 10

first, i notice an exponent of 1 in the denominator of the last problem, so that could be a typo, because usually one does not use 1 as an exponent

Answer 11

second, this is written very sloppily, without making clear what is the input
that is why it is necessary to write \(\ln(x)\) or \(\ln(ab)\) not lnx or lnab

Answer 12

weird, my friend got -5/4 for the third one too O_O

Answer 13

to perhaps whoever wrote this meant for the third one
\[\ln((bc)^2)\] which is different than \(\ln(bc)^2\)

Answer 14

Yeah, it's ambiguous what the exponent is on. If it's squaring the whole log then it would be -5/16, but if it's just squaring the variables (which I thought at first) then it's -5/4.

Answer 15

in other words, they meant find the square of b times c, then take the log of the result
not
find the log of b times c, then square the result

it is sloppy notation, and no wonder you had to waste time on it because it is ambiguous

Answer 16

yea thx guys, i'll try with -5/4 and see

Answer 17

I'd think if it meant to square the variables, it would be written ln(b^2c^2) - that would be consistent with the others . .

Answer 18

but officially, if its written like that, which one does it mean>?

Answer 19

then tell whoever wrote this problem that if they new how to write functions correctly it would not be ambiguous and you would not have to read their minds.
find i gentler way to say it

Answer 20

When in doubt, use more parentheses.

Answer 21

omg finally

Answer 22

it means the author is sloppy, be it your teacher or the idiot who wrote the on line questions
really we write \(f(x)\) not fx

Answer 23

write
complain
it is your right to do so. one thing about math is that ambiguity of this kind cannot be condoned. we should all know what is meant, and all get the same answer. if that is not the case, it is not your fault

Answer 24

lolol

Answer 25

thanks!!!

Answer 26

yw