Trig integration project, hung up on wording and where to start

[8point1]

Homework Statement

Here is a link to the project: http://www.stewartcalculus.com/data/ESSENTIAL%20CALCULUS%20Early%20Transcendentals/upfiles/projects/ecet_wp_0504b_stu.pdf"

I'm on #1 and and I am at a loss to figure out what they are looking for.

This sentence is really giving me trouble: ". . . the best place to sit is in the row where the angle θ subtended by the screen at your eyes is the maximum."

I really don't know where to start, and its making me panic a bit. I understand all the concepts in class (integration) and do well, but this project is throwing me for a loop.

Thanks for any help, it is much appreciated.

Homework Equations

please see link.

The Attempt at a Solution

none yet, still trying to figure out where to go.

 

[8point1]

Okay, started to play with it a bit. Trying to find the length from the wall to the viewer in a straight line.

Came up with (9 + x cos σ), currently trying to find θ with law of cosines...

 

[Trevor Vadas]

The question basically wants you to maximize theta. For question 1, a is the distance from the top of the screen to your eye level and b is the distance from the bottom of the screen to your eye level. Conviince yourself of that by examining the two equations and what each piece represents. Then use the law of cosines to figure out what cos(theta) is.

 

[8point1]

Ok, I finally figured out how to prove the a² and b².

I wasn't using the the alpha triangle to help get the sides I needed. Thank you for your help.