Set a random seed, and then compute the loocv errors that result from fitting the following four models using least squares: i. y = β0 + β1x + ε ii. y = β0 + β1x + β2x2 + ε iii. y = β0 + β1x + β2x2 + β3x3 +ε iv. y = β0 + β1x +β2x2 + β3x3 + β4x4 +ε. note you may find it to use the data. frame() function to create a single data set containing both x and y .

the domain of a function is the set of input values, x , for which a function is defined. the domain is shown in the left oval in the picture below. the function provides an output value, f(x) , for each member of the domain.

25/6

step-by-step explanation:

you multiply 4 by the denominator (4*6=24) and add it to the numerator which makes it 25/6.

(a) x intercepts: -6 and 2

you can obtain these by solving the equation 0=x^2 +4x-12 using your favorite quadratic formula. but it is easy to verify -6 and 2 indeed satisfy this equation.

(b) y intercept: -12

this is obtained by setting x=0: 0^2+4*0-12 = -12

(c) the minimum value is: -16 (this is the vertex)

you can get the vertex by rewriting the equation into the form:

there is no global or local maximum as the function goes to infinity, so only in the limit sense: +infinity.