Hello,
y=2xe^x
y'=2(e^x+xe^x)=2(x+1)e^x
y''=2(e^x+(x+1)e^x)=2(x+2)e^x
x |-infinite -2 0 +infinite
e^x | ++++++++++++++++++
x+2 |------------0 +++++++++++
y'' | -----------0 +++++++++++
y''<0 if x<-2
<span>The interval on which the graph is concave down is (-infinite -2[</span>
Answer:0.29
Step-by-step explanation:
An average of six cell phone thefts is reported in San Francisco per day. This means our mean value, u = 6
For poisson distribution,
P(x=r) = (e^-u×u^r)/r!
probability that four cell phones will be reported stolen tomorrow=
P(x=4)= (e^-6×6^4)/4!
= (0.00248×1296)/4×3×2×1
= 3.21408/24=
0.13392
P(x=5)= (e^-6×6^5)/5!
= (0.00248×7776)/5×4×3×2×1
= 19.28448/120
= 0.1607
probability that four or five cell phones will be reported stolen tomorrow
= P(x=4) + P(x=5)
= 0.13392 + 0.1607
= 0.294624
Approximately 0.29
To divide by a fraction, you multiply by its reciprocal, which you find by flipping the numerator and the denominator. 
Multiply the numerators and the denominators separately. 
Simplify by dividing both sides of the equation by 
. 
Answer:
54.90
Step-by-step explanation:
