Top answers

Express: (x^2 + 5x - 14) / (2x^2 - 4x) as a fraction in it's simplest form.

Answer: (x+7)/(2x)
Answered by • Maths tutor
3888 Views

Make d the subject of the formula: 3d + dxy = 4

d (3 + xy) = 4 d = 4/(3 + xy)
Answered by • Maths tutor
3989 Views

A cylinder has radius 2cm and height 9cm. A cone has radius r cm and height h cm. The ratio r : h is 1 : 4. The volume of the cone is equal to the volume of the cylinder. Work out the value of r.

Firstly, we will find the volume of the cylinder using the formula V_cylinder =π r 2 h . Inputting the numbers given in the question gives V_cylinder = 36π.Given that V_cylinder = V_cone, and using the formu...
AC
Answered by Alice C. • Maths tutor
7236 Views

If y = 1/x^3, find an expression for dy/dx

Write down y = 1/x 3 This can be rewritten as y = 1x -3 or just y = x -3 as if the x is on the bottom of the fraction, it can be rewritten with a negative version of the power 3. A simple way of working this...
PB
Answered by Pete B. • Maths tutor
6884 Views

Prove the identity (sin2x)/(1+(tanx)^2) = 2sinx(cosx)^3

For a proof like this, I like to start with the more difficult-looking side, and aim to end up with the expression on the other side. Starting with the left hand side, the first thing to change is the sin2x,...
AC
Answered by Alice C. • Maths tutor
9669 Views