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Show that (x+1)(x+2)(x+3) can be written in the form ax^3 +bx^2 + cx + d where a,b,c,d are positive integers.

First we shall expand two of the brackets to obtain a quadratic equation and then multiply each term by the remaining bracket. The order with which we expand the brackets does not matter. Use the FOIL met...

Answered by Scott W. • Maths tutor

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Tom thinks of a number. He squares it, adds 3 times the original number and then subtracts 18. The result is 0. What two numbers could Tom have been thinking of?

Formulate the problem algebraically:x²+3x-18=0This is a factorisation problem. To find the solutions, factorise:-Factors of x² are 1 and 1, so answe...

Answered by George H. • Maths tutor

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Prove that the square of an odd number is always 1 more than a multiple of 4

This is a nice little question off the 2018 Edexcel Higher Maths paper! When we heard the word 'prove' in a question at this level, automatically we should be thinking about using algebra to help us out! ...

Answered by Thomas R. • Maths tutor

3327 Views

Let f(x)=xln(x)-x. Find f'(x). Hence or otherwise, evaluate the integral of ln(x^3) between 1 and e.

We use the product rule with u=x and v=ln(x) (so u'=1 andv'=1/x) to differentiate xln(x) to ln(x)+1, and -x just differentiates to -1, hence we have. f'(x)=ln(x).
Now note that ln(x^3)=3ln(x) using p...

Answered by Matthew J. • Maths tutor

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