# How doI solve this?

• May 26th 2011, 06:39 PM
hersheybat11
How doI solve this?
1.sec^x-2tanx=0
2.tan(x/2)=sinx
my teacher game me the answers: for 1 its 45,225 and for 2 its 0, 90, 270.
can you please explain it to me using some simple steps?
thanks
• May 26th 2011, 07:02 PM
pickslides
Is the first question

$\displaystyle \sec x-2 \tan x=0$

or

$\displaystyle \sec^2 x-2 \tan x=0$

??
• May 26th 2011, 07:14 PM
dwsmith
Quote:

Originally Posted by hersheybat11
1.sec^x-2tanx=0
2.tan(x/2)=sinx
my teacher game me the answers: for 1 its 45,225 and for 2 its 0, 90, 270.
can you please explain it to me using some simple steps?
thanks

Your teacher forgot to mention the other infinitely many solutions.

Your solutions should be of the form
$x=\frac{\pi}{6}+\pi k, \ k\in\mathbb{Z}$

That isn't a solution to your questions but merely an example to how the solutions should be represented.