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‘Smokers suffer from more lower respiratory tract infections.’ Justify this statement in light of respiratory tract protection mechanisms.

Smoke contains many harmful chemicals and carcinogens (such as polycyclic aromatic hydrocarbons). There are several ways in which smoking increases the likelihood of lower respiratory tract infections.

Answered by Ali K. • Human Biology tutor

2837 Views

R=1000e^-ct , it takes 5730 years for half of the substance to decay a. find the number of atoms at the start of the decay. b. calculate the number of atoms left when t=22920. c. sketch the function.

a.1000 b. R=62.5 c. Sketch

Answered by Prasad U. • Maths tutor

4621 Views

How do you integrate ln(x)?

I would use the whiteboard and write down y=lnx, and also the integration by parts formula below it. I would then explain how to treat ln(x) as the "u" and "1" as dv/dx; including why ...

Answered by Jamie Z. • Maths tutor

3289 Views

How do you integrate xln(x) between the limits of 0 and 2?

In order to answer this question you need to use integration by parts.Using the standard integration by parts formula: ∫u dv/dx dx = uv-∫v du/dx dx.Let:u=ln(x) v=(1/2)x²du/dx=1/x dv/d...

Answered by Lena K. • Maths tutor

1470 Views

If a rectangle has sides (x+3) and (2x-1) and an area of 15, find x and the length of each side.

To find x, we need to create an expression from the information given. We know the area is 15 and that the area is equal to the length multiplied by the width. This gives us:(x+3)(2x-1) = 15Then we can ex...

Answered by Jasmin L. • Maths tutor

4443 Views