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Sometimes, babies are born with a hole between the right and left ventricles of their heart. Why does this mean oxygenated blood cannot get around their bodies?

Higher pressure in the left ventricle (thicker wall, more contractile power) means that blood will cross from the left side of the heart to the right. This means that not as much oxygenated blood will be pus...
IH
Answered by Isobel H. • Biology tutor
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What is the integral of x^2 sin(x) between the limits 0 and π/2

For this question, we have to integrate x 2 multiplied by sin(x) . For integrating a product, you must use a method called integration by parts. Without bogging ourselves down with the derivation, we know th...
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Answered by Ruth W. • Maths tutor
6997 Views

Explain why the moon is not pulled away from the Earth by the Sun.

The force of gravity decreases very rapidly with distance, since force is inversely proportional to distance 2 . The Sun is much further away from the Moon than the Earth, so its gravitational attraction isn...
AP
Answered by Alicia P. • Physics tutor
4138 Views

Use the chain rule to differentiate y=1/x^2-2x-1

First we will rewrite y so it is written with a power: y=1/x 2 -2x-1=(x 2 -2x-1) -1 Now let u=x 2 -2x-1 => du/dx = 2x -2 Writing y in terms of u: y=u -1 => dy/du= -u -2 = - 1/u 2 using the chain rule: ...
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Answered by Alicia P. • Maths tutor
17975 Views

A house increases by 25% to £80,000. Find what it was worth before the rise.

A 15% increase means that the £80,000 represents 115% of the original value . Therefore what we do is: £80,000=£125% divided by 125 which gives us £640 = 1% then we want to multiply by 100 to change this to ...
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Answered by Alicia P. • Maths tutor
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