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If y=x^3+9x, find gradient of the tangent at (2,1).

To find the gradient of the tangent, we can differentiate to give dy/dx=3x^2+9. We can now put in x=2 to find the gradient at (2,1): 3(2)^2+9=21. Therefore the gradient is 21 at (2,1).
AM
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Solve 7x-4=8+5x

First bring all the x terms to one side by taking 5x from each side, this gives 2x-4=8. Now put all the number terms on the other side by adding 4 to each side, this gives 2x=12. We can now divide both sides...
AM
Answered by Angus M. • Maths tutor
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How does myelination of neurones increase conduction velocity?

Myelination is the production of a myelin sheath - a fatty, electrically insulating layer formed by Schwann cells wrapping around the axons of neurons. This sheath is not continuous, there are gaps between S...
KG
Answered by Kavindi G. • Biology tutor
12799 Views

Describe the process of semi-conservative replication

Process - key words from mark schemes are highlighted in bold 1. The enzyme DNA helicase breaks the hydrogen bonds linking base pairs of DNA. As a result, the double helix unwinds and into two separate stran...
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Answered by Tara C. • Biology tutor
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For a named country which you have studied, describe the problems caused by an ageing population.

Name of country: Japan Japan has a population of 127 million and roughly 23% are over the age of 65 and this huge proportion can prove to be problematic. In general, the elderly require more expensive health...
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Answered by Natasha C. • Geography tutor
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