video1.0<iframe src="https://www.loom.com/embed/40b48e7d3bf14273aee59f13a798bf99" frameborder="0" width="1280" height="960" webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe>9601280Loomhttps://www.loom.com9601280https://cdn.loom.com/sessions/thumbnails/40b48e7d3bf14273aee59f13a798bf99-00001.jpg77p: The function f is defined by f(x) = (x+3)(x+1). The graph of f in the xy-plane is a parabola. Which of the following intervals contains the x-coordinate of the vertex of the graph of f ? a: -4