guys, is there any possibility to obtain field equations of einstein-hilbert action?

best regards

hello , to solve a differential euqations , maple gave me this error. please help me.

TG.mw

hello guys

i have a 2-sphere metric (ds^2=dθ^2+sinθ^2 dφ^2) , how to calculate R^abcd R_abcd . 

thank you very much

hello guys , i have an autonomous system , maple give me this warning when i want to compute its fixed points !

thank you for your time

mm.mw