Report the results of your interview to your classmates. Example: It takes Dasha 20 minutes to get to the nearest stadium.

F(x) = x^3-6*x^2-15*x-2
производная:
f'(x) = 3•x^2-12•x-15
3•x^2-12•x-15 = 0
x1 = -1
x2 = 5

функция убывает на промежутке
(-1; 5)