Integral 0 to 2 e^x dx   
 
 based on trapezoidal rule    
 
 n=1   
 
    8.3890561  
 
 n=2   
 
    6.9128099  
 
 n=4   
 
    6.5216101  
 
 n=8   
 
    6.4222978  
 
 The exact value of intergation is :   
 
    6.3890561  
 
 thus corresponding errors are :    
 
  - 2.         
  - 0.5237538  
  - 0.1325540  
  - 0.0332417  
 
