no because it is not a right angled triangle.
this means angle A is not 90° so AB cant be a tangent.
The solution for this problem would be:
f'(x) = 1 - 1/x^2 = (x^2 - 1)/x^2
is positive where |x| > 1
hence (-inf, -1) and (1, inf) are the regions in which f' is positive and therefore f is increasing.
Therefore, the answer is (-infinity,-1] U [1,infinity).
7(200 + 50 + 6) = (7 x 200) + (7 x 50) + (7 x 6) = 1,400 + 350 + 42 = 1,792
Therefore, slope of line DC = slope of line AC = -0.4.
