Data update

Task/Nth-root/GW-BASIC/nth-root.basic

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+100 REM Nth root
+110 X# = 144
+120 PRINT "Finding the nth root of"; X#; "to 6 decimal places"
+130 PRINT "  x      n        root    x ^ (1 / n)"
+140 PRINT "--------------------------------------"
+150 FOR I% = 1 TO 8
+160  PRINT USING "###   "; X#;
+170  PRINT USING "####    "; I%;
+180  N% = I%: PREC# = .0000001#: GOSUB 1000
+190  PRINT USING "###.######"; NTH.ROOT#;
+200  PRINT USING "    ###.######"; X# ^ (1 / I%)
+210 NEXT I%
+220 END
+1000 REM Calculate the N%th root of value X# to stated precision PREC#
+1010 REM Result: NTH.ROOT#
+1020 X0# = X#
+1030 X1# = X# / N% ' initial guess
+1040 WHILE ABS(X1# - X0#) > PREC#
+1050  X0# = X1#
+1060  X1# = ((N% - 1) * X1# + X# / X1# ^ (N% - 1)) / N%
+1070 WEND
+1080 NTH.ROOT# = X1#
+1090 RETURN