As we know that force F makes an angle of 60 degree with X axis
so the X component is given as
[tex]cos60 = \frac{F_x}{F}[/tex]
now we have
[tex]F_x = F cos60[/tex]
[tex]F_x = 0.50 F[/tex]
Similarly we know that force F makes an angle of 45 degree with Y axis
so the X component is given as
[tex]cos45 = \frac{F_y}{F}[/tex]
now we have
[tex]F_y = F cos45[/tex]
[tex]F_y = 0.707 F[/tex]
Now for the component along z axis we know that
[tex]F_x^2 + F_y^2 + F_z^2 = F^2[/tex]
now plug in all components
[tex](0.707 F)^2 + (0.50 F)^2 + F_z^2 = F^2[/tex]
[tex]0.5 F^2 + 0.25 F^2 + F_z^2 = F^2[/tex]
[tex]F_z^2 = F^2(1 - 0.75)[/tex]
[tex]F_z^2 = 0.25 F^2[/tex]
[tex]F_z = 0.5 F[/tex]