Thread: Logs

Any help please?

Line 1: y = a^x + 1 , a>2
Line 2: y = a^(x+1), a>2

Prove that they intersect when x = loga(1/(a-1))

Originally Posted by kenj

Any help please?

Line 1: y = a^x + 1 , a>2
Line 2: y = a^(x+1), a>2

Prove that they intersect when x = loga(1/(a-1))

The curves:

, and


intersect when:



so:



Rearranging:

,

rearranging:



so taking s to base :



RonL

Sorry - got it ! It was easy once I realised that a^(x+1) is the same as aa^x