Homework Help: Central forces in elliptic and parabolic orbits

hi,can anyone solve this two problems??
these are from the "textbook on spherical astronomy" written by W.smart
chapter five,problem number 18 and 19,Euler's theorem and Lambert's theorem
thank you ;-)

 

yes,this is homework.i have been trying to solve this two question for more than a week,but i cant solve it ;-(

 

nobody????really????

 

dear BruceW,
i have been trying for more than a week,but i cant solve them,so dont tell me that i havent tried !!!!
these are not simple problems :D
bmp files are readible,but i will write down questions right now !!!!

1.if r and r1 are the radii vectors of two points C and C1 in a parabolic orbit and if k is the distance C-C1.prove that the time in the orbit between C and C1 is:

(T0/12pi)[((r+r1+k)/a)^(3/2)-((r+r1-k)/a)^(3/2)]
where T0 is the length of the sidereal year and 'a' is the semi-major axis of the earth's orbit

2.if r and r1 are the radii vectors of two points C and C1 in a elliptic orbit and if k is the distance C-C1.'t' the time required by the planet to move from C to C1 and T the orbital period,prove that:

(2pi*t/T)=H-sin(H)-(H1-sin(H1))

where sin(H/2)=(1/2)((r+r1+k)/a)^(1/2)
sin(H1/2)=(1/2)((r+r1-k)/a)^(1/2)

 

i wont write my workings here,and i think there is no one to help me.this forum is really weak,bye4ever