Question

The polynomial

y=−0.73x4+3.1x3+26.5

describes the billions of flu virus particles in a person’s body x days after being infected. Find the number of virus particles, in billions, after 3 days.

There are billion virus particles in a person’s body 3 days after being infected.

Answer 1

There will be
`51.07` billion virus particles in a person’s body 3 days after being infected.

Explanation:

Step 1:

`y=-0.73 x^(4)+3.1 x^(2)+26.5`

The number of flu particles in a person's body in the billions is represented by y and x represents the number of days after which they have been infected.

So if we need to calculate the number of flu particles in a person's body at any instant of time we just substitute the value of x in y.

Step 2:

To calculate the number of flu virus particles in a person's body after 3 days, we must substitute
`x=3` in y.

`y=-0.73(3)^(4)+3.1(3)^(3)+26.5=-59.13+83.7+26.5=51.07`

So 3 days after being infected there will be
`51.07` billion flu virus particles in that particular person's body.