Search our library of Maths questions

Top answers

Maths

All levels

Given that y = 16x + x^-1, find the two values of x for which dy/dx = 0

Expected layout of answer in an exam:y = 16x + x^-1dy/dx = 16 - x^-2dy/dx = 0 implies that 16 - x^-2 = 0this implies that 16 = x^-216 = 1/x²

Answered by Sawdah H. • Maths tutor

4148 Views

multiply out (2x-4)(x-2) and simplify.

The method I would use here is FOIL (first outer inner last). A common mistake is not multiplying out all terms, using FOIL will ensure you do this.The working I would expect to see:2x^2-4x-4x+8 (order sh...

Answered by Ben W. • Maths tutor

4164 Views

Solve the simultaneous equations: 3x+2y=11, 2x-5y=1.

Step 1) Label Equations 1) 3x+2y=11 2) 2x-5y=1 Step 2) Multiply so that one variable has same coefficient in both equations.1)x5 15x+10y=55 ...

Answered by Harry B. • Maths tutor

5382 Views

Factorise x^2 + 4x +3

First take the 4x - the two numbers that will be +/- to the x in the brackets will need to add to form this number, so the possibilities are 1 and 3 or 2 and 2.Now take the 3 - the two nu...

Answered by James S. • Maths tutor

8180 Views

How to Solve Two Simultaneous Equations

I will use the whiteboard in order to explain the answer to my question. The format will follow:Understanding what it means to 'solve' one equationUnderstanding what it means to 'solve' two equationsVaria...

Answered by Matthew I. • Maths tutor

3060 Views