Answer:
[tex]\sqrt{10}[/tex]/10
Step-by-step explanation:
cos is adjacent side/hypotenuse
you need to find the hypotenuse
Let h = length of hypotenuse
[tex]6^{2} + 18^{2} = h^{2}[/tex]
[tex]h^{2}[/tex] = 36 + 324 = 360
h = [tex]\sqrt{360}[/tex] = 6[tex]\sqrt{10}[/tex]
cos (theta) = 6/6[tex]\sqrt{10}[/tex] = 1/[tex]\sqrt{10}[/tex] = [tex]\sqrt{10}[/tex]/10
