Question

plz help me to solve this I will mark them brainleast ​

Answer 1

Answer:

Substituting the values we get cos(log(x)).cos(log(y))−  

2

1

​

[cos(log(  

y

x

​

))+cos(log(xy))]

=cos(log(x)).cos(log(y))−  

2

1

​

[cos(log(x)−log(y))+cos(log(x)+log(y))]

=cos(log(x)).cos(log(y))−  

2

1

​

[2cos(log(x)).cos(log(y))]=0

Step-by-step explanation:

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Answer 2

Answer:

Now, f [1/x] f (1/y)-1/2 [f (x/y)+f (xy)]

= cos (log 1/x) cos (log1/y)

-1/2 [cos (log x/y) +cos (log (xy))]

= cos (-logx) cos (- log y)

-1/2 [cos (log x - log y)+ (log x + log y)]

= cos (log x) cos ( log y )

-1/2 [2 cos ( log x) cos (log y)]

= cos (log x) cos ( log y) - cos ( log x) cos (log y)

= 0