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Students often encounter (exam) situations in which they are asked to write a type of text (e.g. an email) and incorporate certain aspects.

Possible Question:Du bist mit deiner Familie auf Urlaub und du schickst eine E-Mail an deinen Freund in der Schweiz. Schreib: • etwas über die Unterkunft • wie du dahin gefahren bist • wa...

Answered by Julian R. • German tutor

1820 Views

What is meant by the conservation of energy?

Energy cannot be destroyed or created - it is always transferred between different objects in different forms. Hence, energy is 'conserved'. The most basic example is dropping a stationary rubber ball fro...

Answered by Jonathan H. • Physics tutor

4146 Views

Why is the Mg2+ ion smaller in radius than the Na+ ion?

To answer this we need to compare the two ions. The main difference between the two ions is the number of protons in the nucleus - Magnesium has one more proton than Sodium, however, if you look at the el...

Answered by Jonathan H. • Chemistry tutor

14538 Views

Describe the sequence in which minerals crystallise in a cooling magma using Bowen's Reaction Series.

As a melt cools in a magma chamber is begins to crystallise and becomes a composite mass of solids, the crystals, and liquid, the residual melt. Bowen's Reaction Series gives the order of which the most c...

Answered by Andrew L. • Geology tutor

1957 Views

Using the trigonometric identity for tan(A + B), prove that tan(3x)=(3tan(x)-tan^3(x))/(1-3tan^2(x))

tan(3x)=tan(2x+x), by using the identity for tan(A+B)=(tan(A)+tan(B))/(1-tan(A)tan(B)),tan(3x)=tan(2x+x)=(tan(2x)+tan(x))/(1-tan(2x)tan(x)), using it again for tan(2x),tan(3x)=tan(2x+x)=([(tan(x)+tan(x))/...

Answered by Ivan R. • Maths tutor

10088 Views