CAS calc question

[michael leahcim]

Hi, so I was wondering if there is any function on the calc that would help in verifying answers - especially for multiple choice questions. ie. 'tanx(1 + sec(2x)) equals:' [and then they give a bunch of answers]

I was using the solve function for most of these 'type' of questions and when it had said 'true' as an answer I assumed LHS =RHS, thereby giving you x is an element of all real numbers. But it didn't work for some, so kinda thinking if anyone has had any leads on attempting these kinda questions on the calc 

Also, my calc is the ti-nspire cx model - I've checked the guide on this website, but it didn't have what I was looking for.

[qazser]

Hi, so I was wondering if there is any function on the calc that would help in verifying answers - especially for multiple choice questions. ie. 'tanx(1 + sec(2x)) equals:' [and then they give a bunch of answers]

I was using the solve function for most of these 'type' of questions and when it had said 'true' as an answer I assumed LHS =RHS, thereby giving you x is an element of all real numbers. But it didn't work for some, so kinda thinking if anyone has had any leads on attempting these kinda questions on the calc 

Also, my calc is the ti-nspire cx model - I've checked the guide on this website, but it didn't have what I was looking for.

You can limit domains.
Cntrl =     And select straight line
Then Type Lower Bound of domain
Cntrl = Greater than/Less Than etc.
Type x
Cntrl = Greater than/Less Than etc.
Then Type Lower Bound of domain

Alternatively, can use nsolve (adding an "n" in front of solve) to get whole numbers

[michael leahcim]

But most of these questions don't have a domain to limit. It's mostly just verifying whether or not they are the same that's troubling me - especially with questions in the trig chapter for spesh

[michael leahcim]

On the classpad, there's a judge function which judges if the LHS = RHS. See if the CAS has that.

Ah, did a quick google search and it seems like it's only a classpad thing :''(

[michael leahcim]

Alternatively, can use nsolve (adding an "n" in front of solve) to get whole numbers

Oh, so that's what nsolve is for! haha always wondered what the difference between normal solve and nsolve was!

[MightyBeh]

Do you mean check that 1/x = x^(-1) or something? You can just type it in a calculator page and it'll spit out true if it is.

[qazser]

Do you mean check that 1/x = x^(-1) or something? You can just type it in a calculator page and it'll spit out true if it is.

Yeah forgot about this 

[michael leahcim]

Do you mean check that 1/x = x^(-1) or something? You can just type it in a calculator page and it'll spit out true if it is.

It doesn't work all the time - but I suppose that's the only way we can do it. Especially with the trig questions it's not always entirely guaranteed. eg.  tanx (1+ sec(2x)) should be equal to tan(2x) [this was from the back of the book: i don't really know how they got it] but when I put that in the calc it spits out again as it is.

[MightyBeh]

It doesn't work all the time - but I suppose that's the only way we can do it. Especially with the trig questions it's not always entirely guaranteed. eg.  tanx (1+ sec(2x)) should be equal to tan(2x) [this was from the back of the book: i don't really know how they got it] but when I put that in the calc it spits out again as it is.

Yeah yeah, it's a bit dodgy with trig graphs and some other stuff (fractional powers like x^(3/2), etc). You can also graph the rhs and the lhs to see if they're the same.

[michael leahcim]

oo hadn't thought of that! thanks