| 摘要 |
PURPOSE:To shorten the calculating time by performing the calculation of a trigonometric function with the addition, subtraction and multiplication only and with no division. CONSTITUTION:A 1st memory means 101 stores the value of a sine function and/or the value of a cosine function against the value within one cycle. While a 2nd memory means 102 stores the information corresponding to the input value in a format of floating decimals including the data on an exponential part and a mantissa part. Then a calculation means 103 obtains the corresponding value of a sine function and/or a cosine function against the input value by reference to a 2nd recording means in response to the corresponding mantissa and exponential part data and by reference to a 1st recording medium based on the mantissa part data. The value of the sine or cosine function is calculated to the input value with use of a formula for n-fold angle (n: an integer) of a trigonometric function against the value of the sine or cosine function and the exponential part data. Thus the values of sine and cosine functions can be obtained with the addition, subtraction and multiplication only. In such a way, a desired trigonometric function is obtained in a short time. |
