« first day (1632 days earlier)   

5:11 AM
Hi@PrashinJeevaganth
I got the same answer as per your pic
 
5:23 AM
The directional derivative of $f$ at $P$ in the direction of $(\frac{1}{\sqrt{2}} \hat{i} + \frac{1}{\sqrt{2}}\hat{j})$ is $\nabla f_{P}.((\frac{1}{\sqrt{2}} \hat{i} + \frac{1}{\sqrt{2}}\hat{j})) = (3\hat{i}-4\hat{j}).(\frac{1}{\sqrt{2}} \hat{i} + \frac{1}{\sqrt{2}}\hat{j}) = -\frac{1}{\sqrt{2}}$
.
Also why $e$ has to play a role here? I was thinking how you got an 'e'?
Hope this clears your query!
 

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