# Thread: ERROR: DOMAIN ..when doing sec and cosec..

1. ## ERROR: DOMAIN ..when doing sec and cosec..

Hey I'm so confused, my TI-83 Plus started to give me ERR: DOMAIN today when ever I put a sec or cosec in that isn't equal to 0 or 1. It only just started doing this and I haven't touched anything or changed anything whats going on?

Thanks

Hey I'm so confused, my TI-83 Plus started to give me ERR: DOMAIN today when ever I put a sec or cosec in that isn't equal to 0 or 1. It only just started doing this and I haven't touched anything or changed anything whats going on?

Thanks
No idea, try resetting. If that doesn't work, you can at least work around it by doing 1/cos(x) and 1/sin(x)

A bit of a hassle, sure, but my calculator doesn't even have an option for such functions, it's not too bad. (though not being able to convert decimals to fractions is a pain in the *ahem*)

Hey I'm so confused, my TI-83 Plus started to give me ERR: DOMAIN today when ever I put a sec or cosec in that isn't equal to 0 or 1. It only just started doing this and I haven't touched anything or changed anything whats going on?

Thanks
Hello,

are you sure that you have nowadays a "sec" or "cosec"-key at a TI83?

My TI84 and TI89 don't have such keys. I checked the catalogues and didn't find this function either.

4. Originally Posted by earboth
Hello,

are you sure that you have nowadays a "sec" or "cosec"-key at a TI83?

My TI84 and TI89 don't have such keys. I checked the catalogues and didn't find this function either.
I can't readily check the TI84 but on a TI89 you can get sec( and csc( from the catalogue.

When accessing the catalogue I find it useful to use the alpha key to scroll to the starting character I want (but you sometimes might need to do it twice) ..... alpha 3 (S) gets you to sec(

Hey I'm so confused, my TI-83 Plus started to give me ERR: DOMAIN today when ever I put a sec or cosec in that isn't equal to 0 or 1. It only just started doing this and I haven't touched anything or changed anything whats going on?

Thanks
Are you playing games on it. Some games can do funny things to your settings that aren't immediately obvious.

6. Originally Posted by mr fantastic
I can't readily check the TI84 but on a TI89 you can get sec( and csc( from the catalogue.

When accessing the catalogue I find it useful to use the alpha key to scroll to the starting character I want (but you sometimes might need to do it twice) ..... alpha 3 (S) gets you to sec(
You are right.

I checked if the function "cosec" was build-in, found nothing, and deduced that then the "sec"-function doesn't exist either.

7. i have a TI-83 plus and there is no sec or csc built in. It has sin cos and tan. when you use the 2nd button, sin you get sin^-1, cos gives you cos^-1, and tan you get tan^-1

the only way i have ever been able to enter the sec, csc, and cot is to use the simple formulas
sec= 1/cos
csc= 1/sin
cot= 1/tan

8. ## same problem

When ever I try and enter 2nd sin (sin-1) and cos (cos-1). it comes up with the domain error.

9. Originally Posted by branpera
When ever I try and enter 2nd sin (sin-1) and cos (cos-1). it comes up with the domain error.
1. You have to provide input: $\sin (\sin^{-1} (x))$.

2. Unless you choose a value of x that satifisfies $-1 \leq x \leq 1$ you will probably get a domain error.

What type of calculator do you have and what exactly are you typing into it?

10. ok i was putting in a number bigger than 1. What is sin-1 used for.

11. Originally Posted by branpera
ok i was putting in a number bigger than 1. What is sin-1 used for.
$\sin^{-1}$ is the inverse sine function (arcsin) , not the cosecant function.

### ti 84 plus cos sin tan error domain degree

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