The mosquito population is a function of rainfall, and can be approximated by the formula N(x)=−x3+45x2+1000 where x is the number of inches of rainfall. Find the values of x (if any) so that the population will be a maximum? Note that x is non-negative.

Respuesta :

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

[tex]N(x)= -x^3+45x^2+1000[/tex]

where x is the number of inches of rainfall.

[tex]N(x)= -x^3+45x^2+1000[/tex]

Differentiating with respect to x

[tex]N'(x)= -3x^2+90x[/tex]

Again differentiating with respect to x

[tex]N''(x)=-6x+90[/tex]

Now we set N'(x)=0

[tex]-3x^2+90x=0[/tex]

[tex]\Rightarrow -3x(x-30)=0[/tex]

[tex]\Rightarrow x=0,30[/tex]

[tex]N''(0)=-6.0+90=90>0[/tex]

[tex]N''(30)=-6.30+90=-90<0[/tex]

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.