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What is the cosine rule and when can it be used?

The cosine rule is used to find the length of a side or size of an angle. Take a look at the triangle below: For this triangle we have sides a, b and c and angles A,B and C. For this triangle the cosine rule...
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Answered by Kulvinder L. Maths tutor
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What is homeostasis?

Homeostasis is the maintenance of the internal environment to a constant state, despite changes to the external environment. Examples of conditions in the body which must be kept constant include body temper...
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Answered by George W. Biology tutor
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How do I solve a simultaneous equation?

You will be presented with two equations, both with two unknown values. For example: 8x-2y=19 and 3x=5+y To begin, we are going to move both unknown terms in the second equation to the same side: 3x-y=5 Then...
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Answered by Paul C. Maths tutor
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How do I integrate sin^2(x)?

First, remember the compound angle formula for cosine: cos (2x) =cos^ 2 (x)-sin^ 2 (x). Now use the identity sin^ 2 (x)+cos^ 2 (x)= 1 to give : cos (2x) =(1-sin^ 2 (x))-sin^ 2 (x)=1 -2sin^ 2 (x) Rearranging ...
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Answered by Christopher D. Maths tutor
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Why is the sky blue?

The colour of the sky comes from sunlight scattering off of the air molecules (and to your eyes). Blue light gets scattered more than red light because it has a shorter wavelength, and so the light you see w...
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Answered by Alex P. Physics tutor
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