发明名称 CALCULATOR FOR LOGARITHMIC AND EXPONENTIAL FUNCTION
摘要 PURPOSE:To obtain an inexpensive calculator, by compressing a variable to a value near a prescribed value in a square root extracting means to obtain logarithmic and exponential functions with a small number of constants without changing the coefficient of a series. CONSTITUTION:In the calculator having plural operation registers 13 and a square root extracting means 14, a function f(x) is separated by an expression f(x)=10m.g(x) (m is an integer and 1<=g(x)<1 is true), and a new function g(x) is obtained. In this case, the square root extracting means 14 extracts the square root of a new variable (x), and the extracted square root value is so compressed that it is within a prescribed range, and the extracted square root value or the value obtained by subtracting 1 from this value is substituted only into the lowest term and the next lowest term of exponents in a series or a modified series to obtain the function f(x). Thus, register capacities and operating means which the small-size calculator such as a desk calculator has normally are applied rationally, and a simple and inexpensive calculator for logarithmic and exponential functions is obtained.
申请公布号 JPS57182847(A) 申请公布日期 1982.11.10
申请号 JP19810068001 申请日期 1981.05.06
申请人 EPUSON KK;SUWA SEIKOSHA KK 发明人 FUTAGAWA YOSHIKIYO
分类号 G06F1/02;G06F7/556 主分类号 G06F1/02
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