y = -1/7 x^2 + x - 3
= -1/7 (x^2 - 7x) - 3
now complete the square
y = -1/7 (x^2 -7x + (7/2)^2) - 3 + 1/7 (7/2)^2
y = -1/7 (x - 7/2)^2 - 5/4
Now you can just read off the coordinates of the vertex, no?
graph at
http://www.wolframalpha.com/input/?i=-1%2F7+x^2+%2B+x+-+3
Find the coordinates of the vertex and the equation of the axis of symmetry of the parabola given by the equation.
y = − 1/7 x^2 + x − 3
and graph it
1 answer
1 answer