Express the function f(x) = x 2 + 4x − 1 in standard form by completing the square. Then state the vertex

Answer 1

y = x^2 + 4x -1 = x^2+4x +4 -1-4 = (x+2)^2 -5

f(x) = (x+2)^2 -5

vertex is (-2,-5)