What is the coordinate vector of (1,1)(1, 1)(1,1) in the basis B={(1,2),(2,1)}B = \{(1, 2), (2, 1)\}B={(1,2),(2,1)}?
(−13,23)(-\frac{1}{3}, \frac{2}{3})(−31,32)
(13,13)(\frac{1}{3}, \frac{1}{3})(31,31)
(1,1)(1, 1)(1,1)
(23,−13)(\frac{2}{3}, -\frac{1}{3})(32,−31)