If f(x)=∫₀ˣ e^(t²)(t-2)(t-3) dt for all x ∈ (0,∞), then
f(x)=∫0xet2(t−2)(t−3)dt,x∈(0,∞)
Which of (1)-(4) are TRUE?
1. f′(x) by FTC
2. sign of f′⇒extrema, monotonicity
3. f′′(x)=0 for some c
f′(x)=ex2(x−2)(x−3)(FTC)
ex2>0⇒signf′=sign[(x−2)(x−3)]
f′>0 on (0,2)∪(3,∞),f′<0 on (2,3)
(1): f′ changes +→− at x=2⇒local maximum⇒TRUE
(2): f′<0 on (2,3)⇒f decreasing on (2,3)⇒TRUE
(4): f′ changes −→+ at x=3⇒local minimum⇒TRUE
f′′(x)=ex2[2x(x−2)(x−3)+(2x−5)]=ex2[2x3−10x2+14x−5]
p(0)=−5<0,p(1)=1>0⇒∃c∈(0,1):f′′(c)=0⇒TRUE
All four (1),(2),(3),(4) are TRUE