Which function in vertex form is equivalent to f of x is equal to x squared plus x plus 1 ?
A
f of x is equal to open paren x plus 1 fourth close paren squared plus 5 fourthsB
f of x is equal to open paren x plus 1 half close paren squared plus 3 fourthsC
f of x is equal to open paren x plus 1 fourth close paren squared plus 3 fourthsD
f of x is equal to open paren x plus 1 half close paren squared plus 5 fourths