For a parabola ax² + bx + c the vertex's x equals -b/2a
a = 6 , b = 0
x = -0 / 2*6 => 0
Plug in x = 0 to find the y value :
y = 6 * 0² + 5 - 42 => - 37
Therefore the parabola vertex is :
( 0 , - 37 )
if a < 0 , then the vertex is a maximum value
if a > 0, then the vertex is a minimum value
minimum ( 0, -37 )
hope this helps!