set.seed(123)                        # Create example data
x <- rnorm(100)
y <- rnorm(100) + x+x^2

Method 1

lm(y ~ x + I(x^2) + I(x^3) + I(x^4))

## 
## Call:
## lm(formula = y ~ x + I(x^2) + I(x^3) + I(x^4))
## 
## Coefficients:
## (Intercept)            x       I(x^2)       I(x^3)       I(x^4)  
##     0.05304      0.93261      0.66503      0.01954      0.05998

Method 2

lm(y ~ poly(x, 4, raw = TRUE))  

## 
## Call:
## lm(formula = y ~ poly(x, 4, raw = TRUE))
## 
## Coefficients:
##             (Intercept)  poly(x, 4, raw = TRUE)1  poly(x, 4, raw = TRUE)2  
##                 0.05304                  0.93261                  0.66503  
## poly(x, 4, raw = TRUE)3  poly(x, 4, raw = TRUE)4  
##                 0.01954                  0.05998