Math Is Fun Forum

kappa_am

Member

Registered: 2013-12-20

Posts: 63

Finding COS value from SIN

Hi All,
I need to get COS value from SIN. what I have is COS value and I can determine which region the signal is in. I know that it is simply sqrt(1-sin^2). Since I am working on microcontroller, I need computationally efficient method. It means no SQRT. However, my DSP core has power, divide, ... simple operation like these. I would be grateful if you give me a hint.

Thank you.

Bob

Administrator

Registered: 2010-06-20

Posts: 10,621

Re: Finding COS value from SIN

hi kappa_am

Trouble is: that is the formula for sin into cos.  I don't know of another.  Maybe there's a work around if you say more about how you want to use the result.

Bob

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Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob