Indexing LINEST formula coefficients non-redundantly

[MahTah]

Hello all,
What I find online about how to find LINEST formula coefficients in EXCEL cells (NOT VBA) is introducing INDEX function directly on LINEST function like below:

Equation: y = (c2 * x^2) + (c1 * x ^1) + b
c2: =INDEX(LINEST(y,x^{1,2}),1)
C1: =INDEX(LINEST(y,x^{1,2}),1,2)
b = =INDEX(LINEST(y,x^{1,2}),1,3)

Now, to find all the coefficients, I should actually find 3 times the LINEST coefficients and then on each time index only one coefficients which can be costly on calculation time specially if I have a big set of x and y ranges.
I tried to calculate the LINEST on one cell and then only to index the content of that cell which didn't work. Now the question, What is the clean way to index LINEST coefficients without calculating the whole array of coefficients redundantly?

Thank you in advance for your help,
Mahdi

 

[Eric W]

Let's say that you want to put the LINEST function in A1. What you should do is select A1:C1, and while all 3 cells are still selected, enter your formula in A1, then instead of pressing Enter when you're done, press Control+Shift+Enter. Your 3 coefficients will be in A1:C1.

 

[Tetra201]

Alternatively, you can use =INDEX(LINEST(...),i,j) where i=1,... and j=1,...
to get the m-coefficients, constant b, and additional regression statistics.