If u=logtanπ4+x2, then coshu=
secx
cosecx
tanx
sinx
Explanation for the correct option:
Find the value of coshu :
Given,
u=logtanπ4+x2⇒eu=tanπ4+x2⇒eu=1+tanx21-tanx2
We know,
coshu=eu+e-u2=e2u+12eu
Then,
coshu=1+tanx21-tanx22+121+tanx21-tanx2=1+tanx22+1-tanx2221+tanx21-tanx2=2+2tan2x221-tan2x2=1+tan2x21-tan2x2=1cosx∵cos2x=1+tan2x1-tan2x=secx
Hence, the correct option is A.
Fill in the blanks with >,< or =
-4+-7____-4--7