UPSEE Solved Model Paper 4

We write the second equation as
2cos

1

2

(x+y)cos

1

2

(x−y) =

3

2

2cos(

π

3

)cos(

x−y

2

) =

3

2

2×

1

2

cos(

x−y

2

) =

3

2

cos{

1

2

(x−y)} =

3

2

Since, the range of cos function is [-1,1], so no values of x and y satisfy the second equation. x ∈ φ, y ∈ φ