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How to find the derivative of arctan(x)

Let y = arctan(x). Then x = tan(y). Differentiate using the chain rule and rearrange: d(x)/dx = d(tany)/dx So 1 = sec^2(y) * dy/dx dy/dx = 1/sec^2(y) But from identity sin^2(y) + cos^2(y) = 1 We can derive, ...
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Answered by Matthew R. • Maths tutor
15400 Views

What are some ways to learn noun genders in Spanish?

As all Spanish nouns are classified as either masculine and feminine, I have found several ways of learning how to easily remember and be able to recognise the gender of a noun when I see it written down or ...
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Answered by Henry T. • Spanish tutor
3245 Views

How do I do this question: A small stone is projected vertically upwards from the point A with speed 11.2 m/s. Find the maximum height above A reached by the stone.

[Draw Diagram] We are given the inital velocity u=11.2m/s and we know the acceleration due to gravity is 9.8m/s^2. We need to find the distance 's'. When the stone is at its highest point the velocity will b...
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Answered by Luke W. • Maths tutor
6528 Views

What are some tips for writing an essay in French?

There are several things I try to bear in mind when coming to write a French essay- some which apply to essay writing in general, and others specific to writing in French. Firstly I have found that it is imp...
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Answered by Henry T. • French tutor
9338 Views

What are the light-dependent reactions of photosynthesis?

In the light-dependent reactions, a photon of light hits an electron located in the thylakoid membrane of the chloroplast in photosystem II. This causes the electron to gain energy and jump to a higher energ...
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Answered by Sarah C. • Biology tutor
7133 Views