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y = artanh(x/sqrt(1+x^2)) , find dy/dx

Some of these examiners quite like asking students to find the derivative of an inverse trig or hyperbolic function to try and catch someone off guard. The best way to approach these is to first multiply bot...
EL
7863 Views

simplify and rationalise 1/ sqrt(12)

Start by simplifying the denominator - We can write sqrt(12) as sqrt (4*3). - This can be written as sqrt(4) * sqrt(3) - We know the square root of 4 is 2. sqrt(3) is not a integer so we leave that as sqrt(3...
MF
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Express 2cos(x) + 5sin(x) in the form Rsin(x + a) where 0<a<90

Expanding Rsin(x + a): Rsin(x + a) = Rsin(x)cos(a) + Rcos(x)sin(a) Comparing coefficients of sin(x), cos(x) with first expression leads to: Rsin(a) = 2, Rcos(a) = 5 Dividing these equations gives: tan(a) = 2...
DH
Answered by Dan H. • Maths tutor
12363 Views

How to approach an essay question?

The first step is to read and re-read the question. Work out EXACTLY what the question is asking you for, and what the examiner might want. Remember, you get marks for content, accuracy and structure. The ma...
MS
Answered by Meriel S. • French tutor
2556 Views

if -3 + -4 is -7, is -3 x -4 =-12 (also negative)

I would use the x-y graph to explain the multiplication of negative numbers I would also start with 4 x 3, then work my way towards negative numbers, e.g 4x2, 4x1 ......4x-1, 4x-2 Then I would go from 4 x -3...
SK
Answered by Syeda K. • Physics tutor
2196 Views