Solución:
=> Sen(x)^2 - Cos(x)^2 = 1/2
=> Sen(x)^2 - (1 - Sen(x)^2) = 1/2
=> Sen(x)^2 - 1 + Sen(x)^2 = 1/2
=> 2 Sen(x)^2 - 1 = 1/2
=> 2 Sen(x)^2 = 1/2 + 1
=> 2 Sen(x)^2 = 3/2
=> Sen(x)^2 = 3 /4
.......________.......____
=> V(Sen(x)^2) = V(3/4)
.....................__
=> Sen(x) = V(3) / 2
...........................__
=> X = arcoSen( V(3) / 2)
=> X = +- 60º .......(RESPUESTA).
Espero haberte colbaorado. Suerte.