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Given that x = cot y, show that dy/dx = -1/(1+x^2)

Identify that we are looking at dy/dx, not dx/dy and realise the relationship that dy/dx=1/(dx/dy)2)Try find dx/dy;cot = 1/tan or (tan) -1 Hence, x=(tan y ) -1 implying dx/dy = (-1)(tan y) -2 (sec 2 y ) =(-1...
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Answered by Jacob F. • Maths tutor
12906 Views

Describe the adaptations for efficient gas exchange in the lungs?

For efficient diffusion there must be a concentration gradient that is maintained, a large surface area to volume ration and a short distance for the gases to diffuse across. There are adaptations at the sit...
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Answered by Isla M. • Biology tutor
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Time, T, is measured in tenths of a second with respect to distance x, is given by T(x)= 5(36+(x^2))^(1/2)+4(20-x). Find the value of x which minimises the time taken, hence calculate the minimum time.

To solve this problem we first must look into the given formula for time (T). It is stated, in the question, that the time taken is dependent on distance x. From this we can infer that the following problem ...
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Answered by Aziz H. • Maths tutor
4199 Views

Explain the different situations in which you would use ‘por’ and in which you would use ‘para’

Para: Tiempo futuro próximo (near future time): Tengo que terminar este trabajo para el día Opinión (opinion): Para mí, lo mejor de inglaterra es la educacion - Destinatario (to a person) : ¿Te gusta esta ca...
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Answered by Rachel S. • Spanish tutor
1889 Views

Explain the features and differences between the icehouse and the greenhouse effect?

The globe can experience periods of warming, such as we are experiencing now in the Quaternary period, or it can experience cooling periods leading to ice ages, such as at the Ordovician-Silurian boundary. A...
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Answered by Annabel L. • Geology tutor
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