SOLUTION: Suppose f(x)=A ln(x)+B, where A and B are constants. If f(1)=10 and f(e)=1. what are A and B? What are key algebraic concepts needed to solve the problem?

Algebra ->  Rational-functions -> SOLUTION: Suppose f(x)=A ln(x)+B, where A and B are constants. If f(1)=10 and f(e)=1. what are A and B? What are key algebraic concepts needed to solve the problem?      Log On


   



Question 443318: Suppose f(x)=A ln(x)+B, where A and B are constants. If f(1)=10 and f(e)=1. what are A and B? What are key algebraic concepts needed to solve the problem?
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Suppose f(x)=A ln(x)+B, where A and B are constants. If f(1)=10 and f(e)=1. what are A and B? What are key algebraic concepts needed to solve the problem?
-----------------------
f(x)=A ln(x)+B
f(1) = 10
f(1) = A*ln(1)+B = A*0+B = B
So, B = 10
-------------------
f(e) = 1
f(e) = A*ln(e)+B
f(e) = A*1+B
f(e) = A+B
---
So, A+B = 1
But B = 10,
so A = -9
=================
Cheers,
Stan H.
=============