Question

log7 21

Answer 1

Factor \(21\) and use rules of logarithms.

Answer 2

just plug it in to your updated ti-84

Answer 3

@jinx113, there is absolutely no need.

Answer 4

how in calculator?

Answer 5

Furthermore, that doesn't allow you to express it algebraically.

Answer 6

forget the calculator -.-

Answer 7

relying heavily on calculators results in no understanding, which means failed exams

Answer 8

Calculators are only useful when the computation becomes trivial.

Answer 9

i need an answer though

Answer 10

forget the calculator if you do not want a decimal, but rather another expression involving logs
if you want to know what this number is as a decimal you need
\[\log_7(21)=\frac{\ln(21)}{\ln(7)}\]

Answer 11

@kman1357, I just told you how to get it.

Answer 12

Do you know how to factor and use the rules of logarithms? If not, I can help.

Answer 13

you can write \(21=3\times 7\) so
\[\log_7(21)=\log_7(3)+\log_7(7)=\log_7(3)+1\] but that doesn't tell you what the number is, it just expresses it in a different form

Answer 14

why not? did he specifically ask to express algebraically? the calculator eliminated room for human error. its extraordinarily ignorant to assume that relying on a calculator to do math is destined for failure.

Answer 15

failure in understanding I believe I said

Answer 16

Failure in understanding usually leads to failed exams. Usually.

Answer 17

That, or very poor passing marks.

Answer 18

if you understand why and what youre plugging it in then thats not an issue

Answer 19

depends on the calculator
if your calculator can calculate\[\log_2(4)\]by writing it out directly, you may never acquire an understanding of what a logarithm even is if you just use the calculator

Answer 20

Of course. But most people who rely on a calculator do not understand how the calculator works or what they are plugging in. You are somewhat contradicting yourself.

Answer 21

if, however, you know to use what satellite wrote, that shows an understanding of the formulas involved

Answer 22

I mean for calculators that can only do base 10 or e

Answer 23

to plug it in all you need to do is hit alpha window then select logbase which is option 5 and plug in the variables asked for you will then have your exact answer

Answer 24

exact answer, but that will not enlighten you to the concept of the logarithm; only how to work a calculator

Answer 25

and not an exact answer, but a decimal approximation

Answer 26

and especially considering, for some of us, the regents is tomorrow, its s little late to be doing a full case study on logarithms

Answer 27

@jinx113, you still haven't realized that you either contradicted yourself or used "rely" when you should not have. Here are the top two definitions of "rely":
"Depend on with full trust or confidence.
Be dependent on."
Do you see how your statements contradict themselves if you truly meant to use "rely"?

Answer 28

i do depend/rely on my calculator to do math. what youre saying is that its beneath you to use a calculator. and yes of course it would be ideal for one to fully understand every concept on that test, but for those of us who struggle a calculator is one way to understand. on many occasions i was able to arrive at an understanding by working backwards from an answer on my calculator. who are you to say that that is not an acceptable method?

Answer 29

"what youre saying is that its beneath you to use a calculator."
No.
Me: "Calculators are only useful when the computation becomes trivial."
How can you get from this that it is beneath me to use a calculator? I use them occasionally to check intuition with concrete computation.

"who are you to say that that is not an acceptable method?"
I have not said this. You are misunderstanding me. I believe that if that method works, you should use it. I recommend it, in fact. Understanding is understanding.

My only point is that you were using a word incorrectly. Your entire disagreement with Turing and I hinges on misuse of a word.

Answer 30

ditto^
nice debate y'all, I'm out :)

Answer 31

1. so basically what you just said that the only time calculators become useful is when you grow tired of doing such calculations by hand. hence as a last resort or "beneath" you to go to a calculator first.
2. i am fully aware of the definition of "rely" thank you and i used it where i intended. i never wavered by my argument in my use of rely
3.you on the otherhand have contradicted yourself. do you actually believe that calculators are only useful for trivial work or do you support them as a primary method on the occassion that someone does not understand and comprehend the exact method on how to algebraically express an answer? because you have, in one message, supported both sides of that argument

Answer 32

"you on the otherhand have contradicted yourself. do you actually believe that calculators are only useful for trivial work"

In my case, yes. Occasionally I use them to check my work.

"or do you support them as a primary method on the occasion that someone does not understand and comprehend the exact method on how to algebraically express an answer?"

"I believe that if that method works, you should use it. I recommend it, in fact."
I should have been more specific. I mean that if the method you are using works for you, you should use it. I do not recommend it to everyone. The end goal is knowing how to express the logarithm algebraically; it rarely matters what its actual value is. You should always try to learn forward rather than backward; you happen to do well learning backward. That's fine. I don't mind. I simply do not recommend it to everyone.

Also, 1 is incorrect. I am getting bored of elucidating my points, though. It is becoming confusing and frustrating at this point because I'm not only having to explain the precise meaning of words but also the intended implications.

If you wish to discuss this further, PM me. I do not believe you are understanding me and I do not wish to flood the question with misunderstandings and misinterpretations of what I say.