For all real numbers, f(x)=(x^2+1)/2. If f(a)=25 and f(11)=b, what could be the value of b-a?

Question

I'm confused on how you do these problems. Can someone show me how to do them? Thanks much!

Answer 1

I will start you on b

f(11)=(11^2+1)/2=61 so b is 61

25=(a^2+1)/2 solve for a....

Answer 2

Ok, so f(25)=(25^2+1)/2. 626/2=313. So, a=313. When substituted, 61-313 is -252.

There's a small issue though. This question is multiple, and I don't see a -252 as one of the choices:

a. -14
b. 36
c. 68
d. 77
e. 86

Did I do something wrong?

Answer 3

Shoot I answered this and answer didn't save