All i know is sec is the inverse of cos. see, if it works for you and help you solve your problem.
it is better to say "reciprocal" than "inverse" here. the inverse of $\displaystyle \cos x$ is $\displaystyle \cos^{-1} x$ (or $\displaystyle \arccos x$), and this is different from $\displaystyle \sec x$
Please show me how to work the entire problem out. Thanks.
Jhevon has solved the problem for you as best it can be solved with the information you have given. Are there any further values you have not supplied?
Some of the problems are written very strangly. For example in ther first problem the first sec part of the equation seems to be raised to the power of something. But what?