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Expand and simplify 3(2x + 5) – 2(x – 4)

Firstly, to expand an equation like this, you must multiply the brackets by the number outside of the brackets. Make sure that you multiply every number inside the bracket by the number directly outside, and...
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Answered by Anna K. • Maths tutor
79903 Views

Explain the Chain Rule

The chain rule is used to differentiate composite functions, ie "a function of a function". In this case we have an outer function and an inner function. For example Differentiate f(g(x)). Here f i...
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Answered by Alex C. • Maths tutor
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What is the angle between the position vectors a and b, where a = (6i - j + 3k) and b = (-4i + 2j + 10k)?

cos( AOB ) = a.b /(| a | x | b |) a.b = (6i - j + 3k) . (-4i + 2j + 10k) = (6 x -4) + (-1 x 2) + (3 x 10) = -24 + -2 + 30 = 4 (| a |)^2 = 6^2 + (-1)^2 + 3^2 = 36 + 1 + 9 = 46 -> | a | = 46^(1/2) (| b |)^2...
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Answered by David H. • Maths tutor
6806 Views

What is the myelin sheath?

The myelin sheath is a layer of insulating, fatty material that encases some neurones. The sheath is composed of Schwann cells that have gaps called nodes of Ranvier between them. Potassium and sodium ions c...
AH
Answered by Alice H. • Biology tutor
5437 Views

What is tonality?

Tonality describes what key a piece is in or what tonal relationships are used. When asked to talk about tonality you should discuss whether the key is major or minor and the different modulations used durin...
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Answered by Alice H. • Music tutor
11882 Views