VB编程求前N项和过程y=1+ x^2/(2!)+x^4/(4!)+.x^(2n)/((2n)!)

VB编程求前N项和过程y=1+ x^2/(2!)+x^4/(4!)+.x^(2n)/((2n)!)
补充代码
y=1+ x^2/(2!)+x^4/(4!)+.x^(2n)/((2n)!)
public sub progession(sum#,,eps#)
dim n%,t#
n=2
sum=1
t=1
do while (abs(t)>=eps)
t=
sum=sum+t
n=
loop
end sub
private sub form_click()
dim p1#
call progession(p1,4,0.00001)
print "p1=";p1
end sub