[R] lm coefficients

[Timur Elzhov]

Dear R experts,

Excuse me if my question will be stupid...
I'd like to fit data with x^2 polynomial:

d <- read.table(file = "Oleg.dat", head = TRUE)
d
  X         T
  3720.00   4.113
  3715.00   4.123
  3710.00   4.132
  ...

out <- lm(T ~ poly(X, 4), data = d)
out
  Call:
  lm(formula = T ~ poly(X, 2), data = d)
  
  Coefficients:
  (Intercept)  poly(X, 2)1  poly(X, 2)2  
        9.803     -108.075       51.007  

So, d$T best fitted with function
  9.803 -108.075 * X + 51.007 * X^2,
yes?

T1 <- 9.803 -108.075 * d$X + 51.007 * d$X^2
T1
  705453240
  703557595
  701664500
  699773956
  ...

So, T1 obviosly gets non-sensible values.. :( Why?
Thanks a lot!

--
WBR,
Timur.