Given f(x) = 2x^2 - 5, what is f(3)? 10 points best answer & I'll answer yours :)

So what do I do? Do I just divide both sides by 3 or something?
10 points best answer :D if you want me to answer yours, just ask and I will!

f(x) is a notation in mathematics that states "f as a function of x".
Likewise, f(3) means "f as a function of 3".

In order to find f(3), plug in the value x = 3 every time a x appears in the equation.

Therefore, we have
f(x) = 2x² - 5
f(3) = 2(3)² - 5
= 2(9) - 5
= 18 - 5
= 13

I hope this answers your question.

f(3)=2*3^2-5 substition 3 into the orginal equation and simply...
f(3)=2*9-5=18-5=13...

Can't you replace x by 3 it the formula?

f(3)=2(3)^2-5
=2(3)^-3
=2(1/3^3)
=2(1/27)
f(3)=2/27