## JaySongChang Group Title Find the limit, if it exists. (If an answer does not exist, enter DNE.) Lim x->(pi/2)+ 7e^(tan x) one year ago one year ago

1. JaySongChang Group Title

I thought it would be infinity but apparently infinity is incorrect

2. azolotor Group Title

$\tan(\pi /2) = \sin(\pi /2)/\cos(\pi /2) = 1/\cos(\pi /2)$ Now you can take the left and right hand limits of this to find out if they are equal. In this case they are not so the limit does not exist.

3. JaySongChang Group Title

The answer does not exist is marked incorrectly for this problem.

4. JaySongChang Group Title

I graphed the 7e^(tan x) and it appears that as X approaches pi/2 the graph goes to infinity

5. azolotor Group Title

Only from the right. From the left it approaches 7

6. JaySongChang Group Title

I think the question is only asking for the right hand limit

7. hartnn Group Title

from right its 0, from left its infinity.

8. JaySongChang Group Title

since there is a small + sign the left of the Pi/2

9. JaySongChang Group Title

right*

10. hartnn Group Title

see, from right means x > pi/2 x is in 2nd quadrant where tan x is negative. also, tan pi/2 = infinity so, e^{-infinity} will tend to 0

11. JaySongChang Group Title

thanks a lot!

12. hartnn Group Title

from left means x< pi/2 x is in 1st quadrant where tan x is positive. also, tan pi/2 = infinity so, e^{infinity} will tend to infinity

13. hartnn Group Title

welcome ^_^