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Integrate x*cos(x)

As there are 2 x terms in the integral we will use integration by parts. Remember; ∫u*(dv/dx)dx = uv - ∫v*(du/dx)dx (found by integrating the product rule). From xcos(x) we need to decide which x term will b...
RW
Answered by Rebecca W. • Maths tutor
9745 Views

"Solve cos(3x +20) = 0.6 for 0 < x < 360" - why are there more than one solution, and how do I find all of them?

The important part of this question is to really understand what the cosine function looks like, many students will use their calculators to find arccos(0.6) = 53.13 degrees, but not find the other solutions...
MF
Answered by Martyn F. • Maths tutor
6670 Views

What's the point of writing my mathematics well if I don't get extra marks for it?

Although strictly speaking you get no extra marks for writing out your mathematics clearly and logically, getting into the habit of doing so can help your work in a lot of ways: 1. You can read your work bac...
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Answered by Oliver B. • Maths tutor
4337 Views

Bob has £500 and gives 70% to Edmund and 40% of what is left to George. Work out how much money each person has.

Follow the order of the question- take 70% of £500 = 7 times 10% of £500 = 7x£50 = £350. Therefore Edmund has £350. Bob now has £500-£350=£150. This needs to be split between Bob and George. Using the same m...
DB
Answered by Daniel B. • Maths tutor
2227 Views

A cuboid has sides such that the longest side is two units more than the shortest side, and the middle length side is one unit longer than the shortest side. The total surface area of the cuboid is 52 units². Calculate the length of the shortest side.

The sides of the cuboid are as follows: x, x+1 and x+2. Total surface area of a cuboid is the area of each surface added together. Therefore 2x(x+2)+2x(x+1)+2(x+2)(x+1)= 52 units². 2x²+4x+2x²+2x+2x²+6x+4= 52...
SS
Answered by Sabina S. • Maths tutor
3786 Views