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Prove the change of base formula for logarithms. That is, prove that log_a (x) = log_b (x) / log_b (a).

Firstly, recall the definition of a logarithm: if y = log_a(x), then this means that y is the power you have to raise a to, to get x, that is a^y = x.Now, we want to introduce a new ba...

Answered by Tom H. • Maths tutor

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How do you solve the simultaneous equations x^2+y=1 and -x+y=-1

First rearrange the second equation so that it's equal to y. You do this by adding x and y to both sides of the equation. You should then have y=x-1. Next you should sub y=x-1 into the first equation, x

Answered by Chloe M. • Maths tutor

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(ii) Prove by induction that, for all positive integers n, f(n) = 3^(3n–2) + 2^(3n+1) is divisible by 19

Let P(n) represent the statement that 'f(n) is divisible by 19'. For the basis step, I prove that P(1) is true: f(1) = 3^3(1)-2+ 2³⁽¹⁾⁺¹ = 19. 19 is divisible by 19 so P(1) is true. I...

Answered by Daniel L. • Maths tutor

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Make x the subject of, 4(x+1)/(x+2) = y

The fundamental rule to keep in the back of your head is 'whatever happens to one side must happen to the other'. This way we can be sure that whatever is on the left hand side of the equals sign will be ...

Answered by Jack W. • Maths tutor

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How do you find stationary points of an equation, eg. y=x^2+3x+2

Stationary points of an equation are found where the gradient of the tangent at this point equals zero. A diagram can illustrate this. To find them differentiate the given equation (which gives the gradie...

Answered by Ellie C. • Maths tutor

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