Given that the function 𝑓 of 𝑥
equals negative two 𝑥 squared plus 10𝑥 minus two, where the function’s domain and
range are all reals, determine 𝑓 of three.
We copy down our function. And note that we’re looking for the
function at 𝑥 equals three. So we substitute three for all the
𝑓 values in our function.
Following the order of operations,
we first operate three squared which equals nine. And everything else we’ll bring
down. From there, we multiply from left
to right. Negative two times nine equals
negative 18. 10 times three equals 30.
And we’ll bring everything else
down. Negative 18 minus two equals
negative 20. And we’ll bring down the plus
30. Now we have negative 20 plus 30
which equals 10.
This function at 𝑥 equals three,
𝑓 of three, equals 10.