Differential Equations 2 order and objectives

[layt]

Help pls decide this Differential Equations!I did not coincide with the answer and in some no idea how to do! will be very grateful if you start a proper solution to Us
1) y(4)+2*a2*y''+a4*y= cos(ax)
2) y' = x + 1/y; y(0)=1
3) y' = 2*x + cos(y); y(0) = 0
4) y(x) - λ*(0 to pi)∫(x*sin(t)*y(t)*dt = 0 (find λ and y(x))
5) Parachutist descends on a parachute! Gravity parashyuta F1 = mg, and the force of air resistance F2 = k * v ^ 2, k = const find speed through chute t0 seconds after the shutter and the path traversed by S while!

 

[haruspex]

Pls post your attempted solutions first. (This seems to be the style on this forum.)
In 5), what's S? Is the parachutist going straight down or is there some initial horizontal movement from the aircraft?

 

[layt]

S WAY The past parachuter for t0 seconds
Now throw in a sample solution to my
2 and 3 I solution explains such events
but I do not know to 5 like to approach

 

[HallsofIvy]

Pls post your attempted solutions first. (This seems to be the style on this forum.)

Thanks. It is more than "style"- it is required that you show your own attempts. There are a number of reasons. First this is not a "we do your homework for you so you never have to learn" website! Second, in order to know what kinds of hints will help, we need to know what you do understand about the problem, what kinds of things you have already tried, and where you are having trouble.

In 5), what's S? Is the parachutist going straight down or is there some initial horizontal movement from the aircraft?

 

[haruspex]

S WAY The past parachuter for t0 seconds
Now throw in a sample solution to my
2 and 3 I solution explains such events
but I do not know to 5 like to approach

Sorry, but I didn't understand any of that. Can you get help for your posts from someone with a better command of English?