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Find the constant term in the expression (x^2-1/x)^9

This problem uses the binomial expansion formula: (x+y) n = k=0 Z n n C k x k y n-k .But lets try to understand where this formula comes from by doing the problem without it to start of with.We have the expr...
VY
Answered by Vincent Y. • Maths tutor
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What is the difference between primary socialisation and secondary socialisation? (4 marks)

Primary socialisation is the process through which a child learns the norms, values, and appropriate behaviours for an individual within wider society. This usually takes place within the family, and can inc...
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Answered by Georgia C. • Sociology tutor
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Differentiate: tan(2x) cos(x)

Explain the product rule : d/dx ( f(x) . g(x) ) = f'(x).g(x) = g'(x) . f (x) 2. Briefly run through trigonometric derivatives .* cos (x) differentiates to: -sin(x)* tan (x) differentiates to: sec^2 (x) 3. Br...
SD
Answered by Shreyasi D. • Maths tutor
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Bethan prepared some ethoxyethane (line 6) by reacting ethanol with concentrated sulfuric acid. She used 69g of ethanol (Mr=46) and obtained a 45% yield of ethoxyethane (Mr=74). Calculate the mass of ethoxyethane obtained.

Equation from line 6 is: 2 (ethanol) -------> 1 (ethoxyethane) 2. The ratio of reaction is 2:1. This is the ratio of moles not mass , i.e., 2 moles of ethanol give 1 mole of ethoxyethane. 3. We need to kn...
SD
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Rationalise the fraction : 5/(3-sqrt(2))

To rationalise a fraction we have to eliminate the surds in the denominator. We know we can multiply the top and the bottom of a fraction by the same thing, as this is equivalent to multiplying by 1. Notice ...
MM
Answered by Michael M. • Maths tutor
4794 Views