Thread: inequality

1. inequality

The joint solution of inequality $\displaystyle \log_\pi (x+1)+\log_\pi x<\log_\pi (2x+6)$ is?

Answer:
$\displaystyle \{x \in IR;0<x<3\}$

2. Originally Posted by boy47
The joint solution of inequality $\displaystyle \log_\pi (x+1)+\log_\pi x<\log_\pi (2x+6)$ is?

Answer:
$\displaystyle \{x \in IR;0<x<3\}$
Using the usual log rule and a bit of re-arranging you should get $\displaystyle x^2 - x - 6 < 0$ which has the solution $\displaystyle -2 < x < 3$.

But $\displaystyle \log_{\pi} x$ is only defined for x > 0.

Therefore ....