Search our library of homework questions

Top answers

All subjects

All levels

How can I prove that an angle in a semi-circle is always 90 degrees?

If we take the diameter of a circle and create an angle on the circumference at point C of the circle from the two points where the diameter meets the circumference (points A and B), the angle created wil...

Answered by David W. • Maths tutor

3914 Views

Why are complex ions containing transition elements coloured?

Firstly a transition element is an element which forms one or more stable ions with incompletely filled d orbitals.Ligands are charged or neutral, ions or molecules, which form coordination bonds with a c...

Answered by Josephine R. • Chemistry tutor

9047 Views

Find the partial fraction decomposition of the expression: (4x^2 + x -64)/((x+2)(x-3)(x-4)).

The first step to solving this question is inputting our dummy variables, and laying out the question so we know what we're doing.
So we end up with:(4x² + x - 64)/((x+2)(x-3)(x-4)) =

Answered by Matt V. • Maths tutor

3166 Views

What is the perfect tense and how do you form it?

The perfect tense in Spanish translates as 'to have done something' in English. It is used to express actions that begun in the past and are carried through to the present. For example, 'Todavía no ha tra...

Answered by Lexi R. • Spanish tutor

1599 Views

In an analysis of copper sulfide, 12.7g of copper was found to be combined with 3.2 g of sulfur. Calculate the empirical formula.

So, the empirical formula means the smallest value, like the lowest common denominator in maths, but instead of fractions we are going to be using chemical formulae. I always find it easiest to set it out...

Answered by Serena S. • Chemistry tutor

5286 Views