Evaluate arcsec sec -9pie/7

pleas explain the steps thanks

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- Sep 24th 2009, 02:08 PMkevintrungarcsec proplem pls
Evaluate arcsec sec -9pie/7

pleas explain the steps thanks - Sep 24th 2009, 03:21 PMskeeter
you need to know that the range of the inverse secant function is ...

$\displaystyle \left[0,\frac{\pi}{2}\right) \cup \left(\frac{\pi}{2} , \pi\right]

$

get an angle co-terminal with $\displaystyle \theta = -\frac{9\pi}{7}$ that is in the range of the inverse secant function ...

$\displaystyle \sec\left(-\frac{9\pi}{7}\right) = \sec\left(\frac{5\pi}{7}\right)$

$\displaystyle arcsec\left[\sec\left(\frac{5\pi}{7}\right)\right] = \frac{5\pi}{7}$ - Sep 24th 2009, 04:40 PMkevintrung