Forward difference Newtons formula

[muskan]

please help me to finding out the value of X for forward difference Newtons formula i am tryign since 2 weeks but i fails

where the values of arguments are a1, a1+h, a1+2h, a1+3h
and there cross ponding values are p,q,r,s respectively

 

[muskan]

ques is

F(a) p f(a) p2 f(a) p3f(a) p4f(a)
A1+ h p
A1+ 2h q q-p
A1+3h r r-q r-q-q+p=r-2q+p
A1+ 4h s s-r s-r-r+q = s-2r+q s-2r+q –r +2q-p= s- 3r+3q-p



we find value of a