This problem projects b = (b1,b2...,bm) onto the line through a = (1, 1, 1, ...1). We solve m equations ax = b in 1 unknown (by least squares).
(a) Solve aT a ##\hat{x}## = aT b to show that ##\hat{x}## is the mean (the average) of the b’s.
(b) Find e = b - a ##\hat{x}## and the variance ||e||2...
Hi All,
This question is about vector calculus, gradient, directional derivative and normal line.
If the gradient is the direction of the steepest ascent:
>> gradient(x, y) = [ derivative_f_x(x, y), derivative_f_y(x, y) ]
Then it really confuse me as when calculating the normal line...