The equation of the line of regression of y on x is 3x +2y -26 =0 and that of the line of regression of x on y is 6x + y - 31 =0. Find the angle theta between these two regression lines with the help of correlation coefficient and it's square.I have calculated it with the help of slope formula but when i calculated taking r and it's square, both the answers are different. I think i am somewhere wrong. Help from any member of this forum is appreciated.