If you solve this eq for x: $\displaystyle \ln (5-x^2)=4$
you get:
$\displaystyle x=\sqrt{5-e^4}}$
but that's not defined, is it?
Is it still a correct answer? Since obviuosly if you insert the above for x, you will get 4.
If you solve this eq for x: $\displaystyle \ln (5-x^2)=4$
you get:
$\displaystyle x=\sqrt{5-e^4}}$
but that's not defined, is it?
Is it still a correct answer? Since obviuosly if you insert the above for x, you will get 4.
No, I don't think you did something wrong...
$\displaystyle 5-x^2 = e^4 \approx 54.6$
It means that x^4 must be negative, which we all know can only be positive since the power is even. There are no real solutions.