Microsoft Excel - how can i determine root coefficient (a,b,c,d,e)of polynomial fourth degree with excel?

Asked By bakhtiar mahdi on 14-Mar-18 12:19 PM
ax^4+bx^3+cx^2+dx+e
a=?
b=?
c=?
d=?
e=?                              
                                         
                                          
                     my data                  x              
2.27
4.59
6.55
8.38
9.7
y:
1.934
2.045
2.100
2.096
2.056
STEPHEN DRULEY replied to bakhtiar mahdi on 09-Sep-18 01:24 AM
a = .00005    = x^4 coefficient
b = -.00162   = x^3 coefficient
c = .01098     = x^2 coefficient
d = .02301     = x^1 coefficient
e = 1.84281   = x^0 coefficient

Using Excel plot and trendline, equation overlay
When x = 0   y = e
When x = 7.347 and y = 2.106 = first derivative
Area under the curve = 15.3125