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Show that the derivative of ln(x) = 1/x

We can start by letting y = ln(x) What we are trying to show is that dy/dx = 1/x Since y = ln(x), then e y = e ln(x) = x Taking the derivative of each side of this equation will give us e y .dy/dx = 1 If we ...
JC
Answered by James C. • Maths tutor
11422 Views

Differentiate y = x^3 +x^2 - 4x +5 with respects to x.

When differentiating, you want to use the formula ax^n differentiates to (a n)x^(n-1), so for the example above, x^3 where a is 1, and n is 3, the differentiation is (1 3)x^(3-1) which results to 3x^2. This ...
MS
Answered by Manojhan S. • Maths tutor
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Solve the differential equation: e^(2y) * (dy/dx) + tan(x) = 0, given that y = 0 when x = 0. Give your answer in the form y = f(x).

This is a question taken from a core 4 paper and is a typical example of a differential equation question. The first thing to notice about this equation is that it is "separable", meaning we can re...
DD
Answered by Dominic D. • Maths tutor
12690 Views

Rearranging formulae

Rearrange 1/u + 1/v = 1/f to make u the subject of the formula. Give your answer in its simplest form. There are a number of ways to approach this problem. By subtracting 1/v on both sides we get 1/u as the ...
RS
Answered by Robert S. • Maths tutor
13744 Views

Discuss whether a reduction in taxation will always increase a country’s economic growth rate.

Answers should discuss role of different forms of taxation e.g., income tax, corporation tax, VAT. Better answers will evaluate the potential limitations, and cases in which a reducation may or may not be ef...
AL
Answered by Andrew L. • Economics tutor
4701 Views