1) f(x) = x²(x - 5) = x³ - 5x²
f'(x) = (x³)' - 5(x²)' = 3x² - 10x
f'(2) = 3 * 2² - 10 * 2 = 12 - 20 = - 8
tgα = f'(2) = - 8
α = - arctg8
2) f(x) = x³ - x² - 7x + 6
f'(x) = (x³)' - (x²)' - 7(x)' + 6' = 3x² - 2x - 7
f'(2) = 3 * 2² - 2 * 2 - 7 = 12 - 4 - 7 = 1
tgα = f'(2) = 1
α = π/4