Explanation:
2 x^2 + 6x -1 = 0 for 'completing the square' the lead coefficient must =1
so factor out a 2 from the x parts to get :
2 (x^2 + 3x) - 1 = 0 Now take 1/2 of the 'x' coeffecient ( 3/2) square it (9/4 ) and add it and subtract it from the equation:
2( x^2 + 3x + 9/4 - 9/4) - 1 REDUCE the square
2 ( x + 3/2 )^2 - 18/4 - 1 and simplify
f(x) = 2 (x + 3/2)^2 - 5.5 this is the vertex form of a parabola
vertex = ( - 3/2 , - 5.5 )
axis of symmetry is x = - 3/2
I doubt you can easily 'factor it' , but you can use quadratic formula to find the zeroes ( x intercepts) are x = - 3/2 +- sqrt (11) / 2
y axis intercept occurs when x = 0
putting in x = 0 results in y = - 1