## Easy way to remember sin, cos and tan values

One of my tutees showed me an easy way to remember sin and cos values for the “common” angles, and once you’ve got those you’ve also got tan, cosec, sec and cot.

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Associate Professor in Space Environment at the University of Birmingham, creating the next generation space weather forecast models. Included on Forbes 30 Under 30 list.

# Category: Mathematics

Mathematics## Easy way to remember sin, cos and tan values

Mathematics## Correlation between Astronaut name and Apollo mission

Mathematics## Math(s) can be confusing…

IDL, Mathematics## Standard Deviation in IDL

Mathematics, Misc## Standard Deviation of Noise in TV Viewing Figures

IDL, Mathematics, Misc## Graphical Analysis of Grey’s Anatomy Viewing Figures

Mathematics, Science## Velocity Required for Loop the Loop

Mathematics## Largest Known Prime Number

Mathematics, Science## It’s Snowing Outside!

Mathematics## The Crawshaw Method (for Quadratics)

One of my tutees showed me an easy way to remember sin and cos values for the “common” angles, and once you’ve got those you’ve also got tan, cosec, sec and cot.

Perhaps we’ve finally worked out Deke Slayton’s method for choosing the Apollo crews, basing it on alphabetical order…

I meet a man walking down the street, who I know has two children. He introduces me to his son, what is the probability that his other child is a girl?

The built in IDL standard deviation function in IDL, STDDEV, uses the moment function which treats the standard deviation as a sample, rather than a population. A short programme can give us both options.

As discussed in my last post we found that ‘the standard deviation of the noise in viewers is about 20% of the range of viewers’ for Grey’s Anatomy. I wanted to see if a similar figure was true for other TV shows.

I recently started watching Grey’s Anatomy which I’ve been enjoying. However a friend of mine told me that the later episodes are not as good. So I thought I would have a look if the viewing figures reflected this.

Chris (@chris2306) got asked how fast you would need to be going to complete a loop the loop. This is what we got.

We have a new largest known prime number! So here is an obligatory post about prime numbers.

I’m sitting in my office, at home, watching the snow falling outside and it got me thinking….

Something all GCSE maths students (and above) need to know, and something that a large number of people use everyday, is how to factorize quadratic equations. However I’m amazed how few people know a decent (and easy) way of doing this!