What is the vertex of this quadratic function? f(x) = 10x2 + 5x − 7 a. (0.25, -5.250) b. (0.25, -7.625) c. (-0.25, -5.250) d. (-0.25, -2.525) e. (-0.25, -7.625)

E

Given a quadratic in standard form : y = ax² + bx + c ( a ≠ 0 ), then

The x-coordinate of the vertex is

= -

y = 10x² + 5x - 7 is in standard form

with a = 10, b = 5 and c = - 7, hence

= - = -

Substitute this value into the equation for y-coordinate

y = 10 (- )² + 5 (- ) - 7

  = - - 7

  = - - = -

vertex = (- 0.25, - 7.625 ) → E