SOLUTION: Hello my problem says, let f be the quadratic function given by f(x)=-1/2kx^2+12, where k>0. For what value of k are the roots of the graph -6 and 6? It also says what is f(0)? THa

Algebra ->  Quadratic-relations-and-conic-sections -> SOLUTION: Hello my problem says, let f be the quadratic function given by f(x)=-1/2kx^2+12, where k>0. For what value of k are the roots of the graph -6 and 6? It also says what is f(0)? THa      Log On


   



Question 1013739: Hello my problem says, let f be the quadratic function given by f(x)=-1/2kx^2+12, where k>0. For what value of k are the roots of the graph -6 and 6? It also says what is f(0)? THanks so much for the help!!
Answer by ikleyn(52803) About Me  (Show Source):
You can put this solution on YOUR website!
.
Hello my problem says, let f be the quadratic function given by f(x)=-1/2kx^2+12, where k>0.
For what value of k are the roots of the graph -6 and 6? It also says what is f(0)? THanks so much for the help!!
----------------------------------------------------------------

It is very simple.

Substitute x=6 into the polynomial. You will get

%28-1%2F2%29%2Ak%2A6%5E2+%2B+12 = 0.

Solve it for k.

%28-1%2F2%29%2Ak%2A36 = -12,

k*36 = (-12)*(-2) = 24,

k = 24%2F36 = 2%2F3.