Questions (1 Viewer)

[currysauce]

i ) find d/dx e^(tanx)

did that and got the answer sec²x e^(tanx)

can't do this

ii) hence find integral (e^(tanx) / cos²x) dx

thanks - answer given is e^(tanx) +C

 

[acmilan]

^d/_dx e^tanx = sec²xe^tanx = e^tanx/cos²x (sec²x = 1/cos²x)

^d/_dx e^tanx = e^tanx/cos²x

Anti-derivate both sides:

int (^d/_dx e^tanx) = int (e^tanx/cos²x)
e^tanx + C = int (e^tanx/cos²x)

So int (e^tanx/cos²x) = e^tanx + C

 

[currysauce]

fuck me dead i can be so stupid at times, thanks alot man!