Matrix multiply two lists with a formula

Question

If I have two lists in Excel:

X : x1  x2  x3
Y : y1  y2  y3

How can I make a 2-dimensional matrix like this?:

x1*y1  x1*y2  x1*y3
x2*y1  x2*y2  x2*y3
x3*y1  x3*y2  x3*y3

Answer 1

Assuming X1-X3 is the cells A1:A3 and Y1-Y3 in B1:B3, select a 3x3 range and enter this formula:

=A1:A3*TRANSPOSE(B1:B3)

Enter it as an array formula, i.e. instead of pressing Enter, press Ctrl-Shift-Enter!

Answer 2

Use =MMULT(array1,array2) as an array formula.

for details see.