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Why does 1/x integrate to lnx?

If we let y = lnx, we then know that x = e y . By differentiating both sides of this equation with respect to y we get:dx/dy = e y , as the exponential function differentiates to itself when differentiated w...
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Answered by Chris L. • Maths tutor
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Solve the equation sec^2 x + 2tanx = 0 , 0 ≤ x ≤ 2π, question from HL Maths exam May 2017 TZ1 P1

We start with sec^2 x + 2tanx = 0 for 0 ≤ x ≤ 2π Note that sec^2 x = tan^2 x +1 tan ^2 x + 2tan x +1 = 0 (tan x +1)^2=0 tan x = -1 x=3π/4 or x=7π/4
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Answered by Michał K. • Maths tutor
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y is proportional to x^2 and that when y = 75, x = 5. Find a formula for y in terms of x and find y when x=3

In a proportional equation, you represent the factor of proportionality as k. In this case it means that y=kx^2. In the question you're given a number for both y and x. Sub these in in order to solve for k. ...
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Answered by Kesem I. • Maths tutor
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What is the conservation of mass and what does this mean in relation to equations?

No atoms are lost or made during a chemical reaction, so the total mass of the products is equal to the total mass of the reactants.
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Answered by Kesem I. • Chemistry tutor
2738 Views

Factorise completely x-4x^3

Take out all common factors, in this case only x. This leaves you with x(1-4x^2).Within the brackets you now have a quadratic equation which you can factorise. You need to find factors of -4x^2 that plus to ...
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Answered by Kesem I. • Maths tutor
7054 Views