# Ti Nspire Cas help

• Mar 3rd 2014, 09:59 AM
michellia
Ti Nspire Cas help
This is the question

Find the exact value of sin( X + B ) if sin X = 3/5 and sin B = 5/13. with X in Quadrant 2 and B in quandrant 1

Can figure out most things but not this.

Is there a way to input this in the TI Nspire CAs calculator, and if so, how.

Thanks the test is in two days.
• Mar 3rd 2014, 10:44 AM
Plato
Re: Ti Nspire Cas help
Quote:

Originally Posted by michellia
This is the question
Find the exact value of sin( X + B ) if sin X = 3/5 and sin B = 5/13. with X in Quadrant 2 and B in quandrant 1
Is there a way to input this in the TI Nspire CAs calculator, and if so, how.

$\sin(X+B)=\sin(X)\cos(B)+\sin(B)\cos(X)$

• Mar 3rd 2014, 10:59 AM
michellia
Re: Ti Nspire Cas help
Thank you

How do I enter that into the ti nspire cas and get the answer -63/65
• Mar 3rd 2014, 04:51 PM
Prove It
Re: Ti Nspire Cas help
You aren't going to magically get your CAS to do every bit of work for you.

You have been told \displaystyle \begin{align*} \sin{(X + B)} = \sin{(X)}\cos{(B)} + \cos{(X)}\sin{(B)} \end{align*}.

You already have \displaystyle \begin{align*} \sin{(X)} \end{align*} and \displaystyle \begin{align*} \sin{(B)} \end{align*}, so the things that YOU must do:

1. Find \displaystyle \begin{align*} \cos{(X)} \end{align*} and \displaystyle \begin{align*} \cos{(B)} \end{align*}. The CAS will not do this for you, unless you at least write down a method to go from sines to cosines and then have the CAS do the calculations YOU find.

2. Have the CAS perform the multiplications if you really can't multiply things by hand.

The CAS calculator can not think. So you must!