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How do I find the length of a side of a triangle using the cosine rule?

Suppose we have a triangle with 2 sides of length 4 and 5 (in any units), and the angle between those sides is 60 degrees. We want to find the length of the side opposite the 60 degree angle. Write the cosin...
AH
Answered by Angus H. • Maths tutor
5807 Views

How do you substitute a number into an algebraic expression?

To substitute a number into an algebraic expression, all you need to do is re-write the expression in exactly the same way, except replacing the variable (letter) with the number. It always makes it clearer ...
BH
Answered by Bethany H. • Maths tutor
47606 Views

Find the derivative of x^x

y = x^x -- Yikes! Doesn't that look ugly. It's mostly the x^x part, since ... to the x is fine, and x to the ... is fine. We must split the two x's in order to continue. Perhaps we could log? since then we c...
MD
Answered by Mayur D. • Maths tutor
5700 Views

What is Le Chatelier's principle and how do you apply it to reversible reactions?

Le Chatelier's principle is commonly known as the quilibrium law and it is useful in order to be able to analyse reversible reactions and how changing the conditions will affect which way the reaction will g...
MA
12333 Views

How can I know whether to multiply or add probabilities?

We can only add probabilities when the events are alternatives . For example, let's say we want to calculate the probability that we achieve an A or a B or a C in a given exam. We cannot achieve an A and B f...
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Answered by Nathan O. • Maths tutor
83363 Views