Forum TI-Planet.org

Posted: **19 Apr 2015, 00:30**

Can someone help me with this problem I am having I keep getting an error message and don't know what I am doing wrong. Here is a screen shot of the problem.
Thank you in advance.

Chap 2 problem.jpg

Posted: **19 Apr 2015, 00:54**

Put the square after the parenthesis.
Indeed, tan, sin and cos are functions, which means they need the opening parenthesis to follow by the function name.

In other words, instead of doing tan^2(120), do tan(120)^2, and same for others.

Posted: **19 Apr 2015, 02:22**

I tried that and it gave me an answer of 45/4 and the correct answer I found out was 51/4 but I still don't know how to get to that answer.

Posted: **19 Apr 2015, 09:28**

You "correct" answer is wrong !

$mathjax$\cos(90°)=0$mathjax$

,

$mathjax$\sin(150°)=\frac{1}{2}$mathjax$

and

$mathjax$\tan(120°)=-\sqrt{3}$mathjax$

Hence,

$mathjax$4\tan^2(120°)-3\sin^2(150°)-\cos^2(90°)=4\times 3-3\times\frac{1}{4}-0=\frac{48-3}{4}=\frac{45}{4}$mathjax$

Forum TI-Planet.org

Help with how to solve this!!

Help with how to solve this!!

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Re: Help with how to solve this!!

Re: Help with how to solve this!!