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In a class there are 12 girls and 18 boys. what proportion of the girls are there in the class? Simplify

the total number of students in the class would be 12 girls plus 18 boys which is 30 in total. The proportion of the girls would mean dividing the number of girls by the total number of students so 12/30. as...
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Answered by Ionela M. • Maths tutor
15932 Views

Two numbers add to make 1000. What would they have to be to maximise their product?

We can write the two numbers as x and 1000-x, because x+(1000-x) = 1000 for any x we pick. Now we want to maximise the product x(1000-x); expanding the brackets gives us 1000x-x 2 which is easier to work wit...
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Answered by Ankur D. • Maths tutor
6864 Views

Find the derivative of sin^2(x)

Using the chain rule we differentiate the ‘outside function’, then differentiate the ‘inside function’ and multiply both derivatives together giving 2sin(x)cos(x)
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Answered by David R. • Maths tutor
5294 Views

How do I know which out of the Sine and Cosine rule I should use?

If you look at the formulae for the Sine and Cosine rules you'll see that the Sine rule involves two angles and two sides and the Cosine rule involves one angle and three sides.So have a look at the problem ...
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Answered by Julian H. • Maths tutor
5687 Views

Find an expression in terms of powers of cos(x) for cos(5x)

De Moivre's theorem states that e ix = cos(x) + isin(x) or that e i5x = cos(5x)+ isin(5x). If the real components of both sides of this equation is taken we can see that : cos(5x) = Re[e i5x ] where Re means...
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Answered by Arnav A. • Maths tutor
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