Thread: Evaluate this function

1. Evaluate this function

evaluate this function F(x)= 2[[x+7]]-8 at the indicated values:

i) f(3)
ii) f(-3.3)
iii) f(3/4)

i dont know why when i plug in ii) and iii) i dont get the right answer. when i plug in i) f(3) i get 12 which is the correct answer for that values but the other two is way off. what should i do?

2. Originally Posted by refresh
evaluate this function F(x)= 2[[x+7]]-8 at the indicated values:

i) f(3)
ii) f(-3.3)
iii) f(3/4)

i dont know why when i plug in ii) and iii) i dont get the right answer. when i plug in i) f(3) i get 12 which is the correct answer for that values but the other two is way off. what should i do?
$\displaystyle -3.3+7=3.7$, so $\displaystyle [[3.7]]=3$ and $\displaystyle 2\cdot3-8=-2$

3. Originally Posted by redsoxfan325
$\displaystyle -3.3+7=3.7$, so $\displaystyle [[3.7]]=3$ and $\displaystyle 2\cdot3-8=-2$
i dont understand how [[3.7]] is 3?

4. Is that not the greatest integer (floor) function?

5. Originally Posted by redsoxfan325
Is that not the greatest integer (floor) function?
ok so for [[3/4+7]] would that be 4????