If `cos^(-1).(x)/(2) + cos^(-1).(y).(3) = (pi)/(6)`, then prove that `(x^(2))/(4) - (xy)/(2sqrt3) + (y^(2))/(9) = (1)/(4)`

Explanation

`cos^(-1) ((x)/(2)) + cos^(-1) ((y)/(3)) = (pi)/(6)`
`rArr cos^(-1) [(xy)/(6) - sqrt(1 -(x^(2))/(4)) sqrt(1 - (y^(2))/(9))] = (pi)/(6)`
`= rArr ((xy)/(6) -(sqrt3)/(2))^(2) = (1- (x^(2))/(4)).(1-(y^(2))/(9))`
`rArr (x^(2))/(4) - (xy)/(2sqrt3) + (y^(2))/(9) = (1)/(4)`