<span>The factors of 60 are 60, 30, 20, 15, 12, 10, 6, 5, 4, 3, 2, 1.The factors of 75 are 75, 25, 15, 5, 3, 1.<span>The common factors of 60 and 75 are 15, 5, 3, 1, intersecting the two sets above.</span><span>In the intersection factors of 60 ∩ factors of 75 the greatest element is 15.</span><span>Therefore, the greatest common factor of 60 and 75 is 15.
The derivative, f'(x) = 6x^2+1, is never negative, so f(x) is monotonic, hence invertible.
f'(-2) = 6(-2)²+1 = 25
If point (-2, -26) is on the graph of function f(x), and the slope is 25 there, then (-26, -2) is on the graph of f⁻¹(x), and the slope is 1/25 there. The equation of the tangent line throught that point can be written in point-slope form as