Mathemeticians (but not EEs) use the symbol i for the square root of -1, which is an "imaginary number". (EEs use j instead of i, to avoid confusion with electrical current i)
Pi is a "rational number", meaning it can be expressed as a fraction. Pi is exactly 22/7, or approximately 3.14159.....
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Electrical Engineer by day, Woodworker by night
Mathemeticians (but not EEs) use the symbol i for the square root of -1, which is an "imaginary number". (EEs use j instead of i, to avoid confusion with electrical current i)
Pi is a "rational number", meaning it can be expressed as a fraction. Pi is exactly 22/7, or approximately 3.14159.....
we (EEs) use i for the "imaginary" number and sometimes j. Its usually not confusing due to the context.
actually 22/7 is not exactly pi, it's a close approximation*. so altho 22/7 is rational. there is no rational value for pi.
*Pi and 22/7 start to differ around the third decimal point.
Pi is 3.14159...
22/7 is 3.14285...
so 22/7 is about .04% off, good enough for most calculations and easier to remember than a string of 5 digits which is why its popularly called Pi.
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