Question

найдите точку максимума функции y=t^3-3t^2-9t-4

Answer 1

y=t³-3t²-9t-4
y'=3t²-6t-9
y'=0
3t²-6t-9=0
D=36+108=144=12²
t=(6±12)/6
t1=3;t2=-1
y'>0
y'<0
3t²-6t-9>0
t€(- ;-1)U(3;+ )
3t²-6t-9<0
t€(-1;3)
__+__-1___-__3___+
x=-1max
x=3 min