Musical instruments that start with the letter I include the igil, ipu, Irish uillean, Irish bouzouki, ichigenkin, inci, iya, itotele and istarski mih. The instruments originate from countries ranging from Cuba and Ireland to Croatia, Japan and the Philippines.
Bessel's functions are often used in acoustics for describing circular membranes behaviour (exploited by most of the musical instruments). They are the solutions of the wave equations using polar coordinates. Set the properties of the membrane Bessel's functions describe the vibrational modes of the membrane.
The Microsoft Excel TEXT function returns a value converted to text with a specified format. The TEXT function is a built-in function in Excel that is categorized as a String/Text Function. It can be used as a worksheet function (WS) in Excel. As a worksheet function, the TEXT function can be entered as part of a formula in a cell of a worksheet.