Concept Used: sinA=sinB then A=B cosA=cosB then A=B Where 0≤A,B≤90∘ Formula Used:
cos90∘=0,sin30∘=1∕2,cot90∘=0 Calculation: We have cos(x+y)=0 ⇒cos(x+y)=cos90∘ ⇒cos(x+y)=cos90∘ ⇒x+y=90∘ And sin(x−y)=
1
2
⇒sin(x−y)=sin30∘ ⇒x−y=30∘ On adding equation (i) and (ii), we get 2x=120∘ ⇒x=60∘ Now, From (i) 60∘+y=90∘ ⇒y=30∘ Now, We have to find cot(2x−y) So, cot(2×60∘−30∘)=cot90∘=0 ∴ The value of cot(2x−y) is 0 .