hi evrybody, this group is full of Vba experts hope sumbosy help me
out in my problem

i want to get Trendline Coeeficients for second degree polynomial i
have recorded macro to calculate coefficients

but i want VBa procedure which can compute coeeficients for variable
no. of rows

in the procedure below i have to change the value of "i"
which is i = 81 below i have to change evrytime dat varies how can i
calculate "i" dynmaically

Sub Button1_Click()

' y = p*x^2 + q*x + r

For j = 1 To 81 Step 5

x0 = Cells(j + 2, "a").Value
xn = Cells(j + 6, "a").Value

Cells(j + 2, "g").Value = x0
Cells(j + 2, "h").Value = xn

Cells(j + 2, "D").Select
ActiveCell.FormulaR1C1 = _
"=INDEX(LINEST(RC[-2]:R[2]C[-2],RC[-3]:R[2]C[-3]^{1,2}),1)"
Cells(j + 2, "E").Select
ActiveCell.FormulaR1C1 = _
"=INDEX(LINEST(RC[-3]:R[2]C[-3],RC[-4]:R[2]C[-4]^{1,2}),1,2)"
Cells(j + 2, "F").Select
ActiveCell.FormulaR1C1 = _
"=INDEX(LINEST(RC[-4]:R[2]C[-4],RC[-5]:R[2]C[-5]^{1,2}),1,3)"

p = Cells(j + 2, "d").Value
q = Cells(j + 2, "e").Value
r = Cells(j + 2, "f").Value

hope somebody find time to give your valuable suggestions

thanx alot