Deriving/Solving sin/cos/tan 'n1,n2 etc...'

[geoff_821]

So I'm doing the 2010 VCAA Methods Exam - Exam 2
I'm on question 3 - extended response with the pyramid thing.
On part e, it asks to find the max volume, where u must derive the volume and let it equal to zero and find the values of x.
I have derived it successfully,
however when I type the derived function into my TI-nSpire CAS Calculator, let it equal to zero and solve I get:

"x= 2•n11•π + "  cos^(-1)⁡〖√3/3〗  or x="2•n11•π - "  cos^(-1)⁡〖√3/3〗  etc….


gahh ^ that formula just failed, but i hope you get what i'm tryna ask. how do i overcome this whole n11 shit?

[b^3]

Define the domain by adding what is in the quote marks "|lowerbound<=x<=upperbound" after you close the bracket for the solve

[TrueTears]

never ever solve for trig functions with a domain, why? you get infinite solutions

[geoff_821]

Define the domain by adding what is in the quote marks "|lowerbound<=x<=upperbound" after you close the bracket for the solve

oh yeah I did that also.

has anyone done this question? how did u get around to ur solution?

[b^3]

never ever solve for trig functions with a domain, why? you get infinite solutions

Do you mean with a domain or without a domain?

[Greatness]

when you solve, at the end of the calculator syntax put | (given that sign) domain. So something like:
solve(sin(x)=1/2,x)|0<x<2TT

[BubbleWrapMan]

0<x<π/2 for the shape to exist.

[TrueTears]

never ever solve for trig functions with a domain, why? you get infinite solutions

Do you mean with a domain or without a domain?

without* loooooooooool

also if you're not sure about which domain you need to solve for, sometimes just put a large domain and the calc will give you plenty of answers to choose from

[geoff_821]

All is solved, tried the question today (with the domains) and it worked, dunno what I was doing wrong last night.
Cheers for the help!