2 cos x = sec x

Thank you ahead of time.

Printable View

- Dec 16th 2008, 04:14 PMakpolishTrig. Finding the general solution
2 cos x = sec x

Thank you ahead of time. - Dec 16th 2008, 04:23 PMchabmgph
- Dec 16th 2008, 04:25 PMakpolish
Thank you for the hint but I still don't understand.

- Dec 17th 2008, 03:36 PMchabmgph

$\displaystyle 2 \cos x = \sec x$

$\displaystyle 2 \cos x =\frac{1}{\cos x} \text{ \; \; \; \; (}\cos x \neq 0$)

$\displaystyle 2 \cos^2 x =1$

$\displaystyle \cos^2 x =\frac{1}{2}$

$\displaystyle \cos x =\pm\frac{\sqrt{2}}{2}$

Now see if you can find the angles which gives you these value.