Statistical univariate linear regression proved that SST = SSE + SSR How to prove the unitary linear regression SST = SSE + SSR,

Statistical univariate linear regression proved that SST = SSE + SSR How to prove the unitary linear regression SST = SSE + SSR,

Because the one variable linear regression equation requires the least sum of squares from the regression when it is established, that is, the regression equation is established according to the principle of "least square method". On this basis, it can be proved that SST = SSE + SSR, as shown in the picture