Routines 
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The address of this routine is found in the table of addresses. It is called via the calculator literal 31 by the routines at DRAW, CD_PRMS1 and tan. It is also called indirectly via fp_calc_2.
This subroutine handles the function SIN X and is the third of the four routines that use the series generator to produce Chebyshev polynomials.
The approximation to SIN X is found as follows:


sin  14261  RST 40  X  
Perform step i.


14262  DEFB 57  get_argt: W  
Perform step ii. The subroutine from now on is common to both the SINE and COSINE functions.


C_ENT  14263  DEFB 49  duplicate: W, W  
14264  DEFB 49  duplicate: W, W, W  
14265  DEFB 4  multiply: W, W*W  
14266  DEFB 49  duplicate: W, W*W, W*W  
14267  DEFB 15  addition: W, 2*W*W  
14268  DEFB 161  stk_one: W, 2*W*W, 1  
14269  DEFB 3  subtract: W, 2*W*W1=Z  
Perform step iii, passing to the series generator the parameter '6' and the six constants required.


14270  DEFB 134  series_06: W, Z  
14271  DEFB 20,230  
14273  DEFB 92,31,11  
14276  DEFB 163,143,56,238  
14280  DEFB 233,21,99,187,35  
14285  DEFB 238,146,13,205,237  
14290  DEFB 241,35,93,27,234  
At the end of the last loop the 'last value' is (SIN (π*W/2))/W.
Perform step iv.


14295  DEFB 4  multiply: SIN (π*W/2)=SIN X (or COS X)  
14296  DEFB 56  end_calc  
14297  RET  Finished: 'last value'=SIN X (or COS X). 
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