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How do I approach a question that asks me to analyse sources?

The first thing to keep in mind for source questions is to cover all the sources in your answer equally. In an A Level question, you will usually be given 4 and it's perfectly fine to structure your answer a...
MG
Answered by Marine G. • History tutor
3640 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 elect...
JH
16601 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 comm...
AL
Answered by Andrew L. • Geology tutor
2588 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))/(1-...
IR
Answered by Ivan R. • Maths tutor
11592 Views

a curve is defined by y=2x^2 - 10x +7. point (3, -5) lies on this curve. find the equation of the normal to this curve

equation of tangent is y - y1 = m(x-x1). differentiating y gives us the value of m. so dy/dx = 4x-10. we know x is 3. therefore, dy/dx = m = 2 but we need equation of the normal, which is y-y1=(1/m)(x-x1). 1...
HH
Answered by Huy H. • Maths tutor
4071 Views