If A = arctan(2/3) and B = arctan(1/2), find tan (A + B).

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- May 5th 2009, 09:18 PMmagentaritatan (A + B)
If A = arctan(2/3) and B = arctan(1/2), find tan (A + B).

- May 5th 2009, 09:35 PMProve It
- May 6th 2009, 05:23 AMmagentaritaI know but...
- May 6th 2009, 02:43 PMProve It
$\displaystyle \tan{(\arctan{\theta})} = \theta$.

- May 6th 2009, 06:16 PMmagentaritaare you
- May 6th 2009, 06:55 PMChris L T521
No. What he's saying is that $\displaystyle \tan\!\left(\arctan\!\left(\tfrac{2}{3}\right)\rig ht)=\tfrac{2}{3}$ and $\displaystyle \tan\!\left(\arctan\!\left(\tfrac{1}{2}\right)\rig ht)=\tfrac{1}{2}$.

Your $\displaystyle A$ and $\displaystyle B$ values are still those arctangent values, but when you substitute them into your identity, you take into consideration what ProveIt told you (and what I elaborated above). - May 7th 2009, 06:05 AMmagentaritacan you
- May 7th 2009, 06:12 AMmr fantastic
- May 7th 2009, 06:13 AMmagentaritaok