insight 2010 exam 2 question

[guns_of_the_patriots]

hi guys . im stumped on question 3 of the short answer part in insight 2010 exam .
can sum one explain to me how to get 3a and b? and if u could the whole question insight dont really explain it too good . anyways its here http://vcenotes.com/forum/index.php/topic,29541.0.html

thanks

[Elnino_Gerrard]

Solve=0 for x. Give it a domain. say till3pie? U know the graph begins to repeat from the 3rd x intercept which is pie. So period=pie.
A is the 2nd x intercept which is pie/4
B is the 4th x intercept. which is 5pie/4

[guns_of_the_patriots]

thanks champ . i just had problems entering into my nspire cos i didnt exapnd it first but thanks a lot