Answer:
x = 5[tex]\sqrt{2}[/tex]
Step-by-step explanation:
Using the cosine ratio in the right triangle and the exact value
cos45° = [tex]\frac{1}{\sqrt{2} }[/tex], then
cos45° = [tex]\frac{adjacent}{hypotenuse}[/tex] = [tex]\frac{x}{10}[/tex] = [tex]\frac{1}{\sqrt{2} }[/tex] ( cross- multiply )
x × [tex]\sqrt{2}[/tex] = 10 ( divide both sides by [tex]\sqrt{2}[/tex] )
x = [tex]\frac{10}{\sqrt{2} }[/tex] × [tex]\frac{\sqrt{2} }{\sqrt{2} }[/tex]
= [tex]\frac{10\sqrt{2} }{2}[/tex] = 5[tex]\sqrt{2}[/tex]
