Help me please , will mark brainliest

The mosquito population is a function of rainfall, and can be approximated by the formula N(x)=−x3+45x2+1000 where x is the numb

KiRa [710]

Answer:

Therefore the population will be maximum when x=30 inches.

Step-by-step explanation:

Given that, the mosquito population is a function of rainfall and can be approximated by the formula

$N(x)= -x^3+45x^2+1000$

where x is the number of inches of rainfall.

$N(x)= -x^3+45x^2+1000$

Differentiating with respect to x

$N'(x)= -3x^2+90x$

Again differentiating with respect to x

$N''(x)=-6x+90$

Now we set N'(x)=0

$-3x^2+90x=0$

$\Rightarrow -3x(x-30)=0$

$\Rightarrow x=0,30$

$N''(0)=-6.0+90=90>0$

$N''(30)=-6.30+90=-90$

Since at x=30, N''(x)<0, So at x=30, N(x) has maximum value.

Therefore the population will be maximum when x=30 inches.

5 0

2 years ago

Three randomly selected households are surveyed. /The numbers of people in the households are 1, 3, and 8. Assume that samples o

inn [45]

The question is asking to find the variance for the said samples in the problem ans use the sample data to determine each variance, and base on my further computation and further calculation, I would say that the answer would be the following:
#1. 3.3 -> 1 and 3 -> 2/9
#2. 1-> 0->3/9
#3. 6.3 - > 8 and 3-> 2/9
#4 49-> 1 and 8-> 2/9

8 0

3 years ago

Given the following formula, solve for I. P = 2(1 + 6) PLEASE HELP!!!

Pepsi [2]

Step-by-step explanation

Here ...I'm not too sure about the question as you have written

P = 2 ( 1 + 6 ) and ask to solve for L ...

.So I guess the question you have written is wrong .. ...and I guess there should be L in the place of 1.

...So let me correct the question....

P = 2 ( l + 6 )

P = 2l + 12

P - 2l = 12

- 2l = 12 - P

- 2l = - P + 12

Change the sign of both side of the equation...

2l = P + 12

divide both side by the same number...

L = ( P + 12 ) ÷ 2

$l = \frac{1}{2} p - 12 \times \frac{1}{2} \\$

Calculate the product of rational numbers...

$l = \frac{1}{2} p - 6 \\$

5 0

2 years ago

What is 1.7a+0.3a=4/5??? Halp me plz...

Ray Of Light [21]

1.7a+0.3a=4/5
2a = 4/5
a = 4/5 * 1/2
a = 4/10
a = 2/5

6 0

3 years ago

Read 2 more answers

Please solve each of the following by factoring!

Oxana [17]

Answer:

see explanation

Step-by-step explanation:

(a)

x² - 36 = 0 ← is a difference of squares and factors as

(x - 6)(x + 6) = 0

equate each factor to zero and solve for x

x + 6 = 0 ⇒ x = - 6

x - 6 = 0 ⇒ x = 6

(b)

x² - 5x + 4 = 0

consider the product of the factors of the constant term (+ 4) which sum to give the coefficient of the x- term (- 5)

the factors are - 1 and - 4 , since

- 1 × - 4 = + 4 and - 1 - 4 = - 5 , then

(x - 1)(x - 4) = 0 ← in factored form

equate each factor to zero and solve for x

x - 1 = 0 ⇒ x = 1

x - 4 = 0 ⇒ x = 4

(c)

x² - 2x = 3 ( subtract 3 from both sides )

x² - 2x - 3 = 0 ← in standard form

consider the product of the factors of the constant term (- 3) which sum to give the coefficient of the x- term (- 2)

the factors are + 1 and - 3 , since

1 × - 3 = - 3 and 1 - 3 = - 2 , then

(x + 1)(x - 3) = 0 ← in factored form

equate each factor to zero and solve for x

x + 1 = 0 ⇒ x = - 1

x - 3 = 0 ⇒ x = 3

(d)

6x² - 11x - 10 = 0

consider the product of the factors of the coefficient of the x² term and the constant term which sum to give the coefficient of the x- term.

product = 6 × - 10 = - 60 and sum = - 11

the factors are + 4 and - 15

use these factors to split the x- term

6x² + 4x - 15x - 10 = 0 ( factor the first/second and third/fourth terms )

2x(3x + 2) - 5(3x + 2) = 0 ← factor out (3x + 2) from each term

(3x + 2)(2x - 5) = 0

equate each factor to zero and solve for x

3x + 2 = 0 ⇒ 3x = - 2 ⇒ x = - $\frac{2}{3}$

2x - 5 = 0 ⇒ 2x = 5 ⇒ x = $\frac{5}{2}$

6 0

2 years ago