Respuesta :

[tex]\sqrt{2}[/tex]Answer:

Step-by-step explanation:

now the equations looks like

5-4*Cos(x) = y

when 45° gets plugged into Cos(x) we get [tex]\sqrt{2}[/tex]/2 again

5- 4 * ([tex]\sqrt{2}[/tex]/2) = y

5-2[tex]\sqrt{2}[/tex]=y

leave it in that form . it's exact that way