Answer:
x = [tex]\frac{9\sqrt{2} }{2}[/tex]
Step-by-step explanation:
Using the cosine ratio in the right triangle and the exact value
cos45° = [tex]\frac{\sqrt{2} }{2}[/tex]
cos45° = [tex]\frac{adjacent}{hypotenuse}[/tex] = [tex]\frac{x}{9}[/tex]
Multiply both sides by 9
9 × cos45° = x , that is
9 × [tex]\frac{\sqrt{2} }{2}[/tex] = x, hence
x = [tex]\frac{9\sqrt{2} }{2}[/tex]
