Question

How do you find the vertex of `f(x)= -6x^2+ 5x + 18`?

Answer 1

`(5/12,457/24)~~(0.42,19.04)`

Explanation:

Using:
`v_x=(-b)/(2a)`

`v_x=(-5)/(2*(-6))=(-5)/(-12)=5/12~~0.42`

and now substituing in the function equation,
`f(5/12)=-6*(5/12)^2+5*5/12+18=457/24~~19.04`

so the vertex is point `(5/12,457/24)~~(0.42,19.04)`.