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Identify which 2 of the following processes involve an exothermic change: melting, boiling, freezing, deposition and sublimation

An exothermic reaction involves an output of heat, so heat is lost overall. This would mean that boiling and melting are definitely not exothermic as they involving putting in heat. Free...

Answered by Ellen S. • Chemistry tutor

6376 Views

Integrate (12x^5 - 8x^3 + 3)dx giving the terms of the answer in the simplest terms

Integration is essentially differentiation in reverse! So in the simpler cases instead of multiplying by the power of x and subtracting one from the power of x, you add one to the power of x and divide by...

Answered by Ellen S. • Maths tutor

6546 Views

(C3) Show that 4csc^2(x) - cot^2(x) = k can be expressed as sec^2(x) = (k-1)/(k-4) where k != 4

The student can answer this in several ways. One using the simple, known identities csc= 1/sin, cot=1/tan, sec=1/cos, tan=sin/cos, sin^2 + cos^2 = 1 and basic algebra is the following:
4csc^2 - cot^2...

Answered by Fearghus H. • Maths tutor

3856 Views

Find the binomial expansion of (-8+4x)^(2/3) up to and including the term in x^2.

The formula booklet is useful for this type of question, but only once we've rearranged the expression into the correct form. The formula booklet expression is: (1 + z)^n = 1 + nz + 0.5n*(n-1)

Answered by David M. • Maths tutor

4354 Views

Explain the key purposes of the UN [15]

The United Nations was established through the San Francisco Conference in 1945 with current membership now at 193 states. It is the successor to the failed League of Nations. Its principle aims, spelled ...

Answered by Nicholas G. • Politics tutor

2538 Views