In the function rule f x 2 squared x-4 find f 4?

To find ( f(4) ) in the function rule ( f(x) = 2x^2 - 4 ), substitute ( x = 4 ) into the equation. This gives:

[ f(4) = 2(4^2) - 4 = 2(16) - 4 = 32 - 4 = 28. ]

Thus, ( f(4) = 28 ).