Answer:
b. [tex]b.) \frac{\sqrt{2} }{2}[/tex]
Step-by-step explanation:
Whenever you are given a question like this
(either triangle has 30-60-90 angles or 45-45-90)
you use the special triangle formula
So since this is a special triangle with 45-45-90 angles
and you are looking for cos 45° (which is [tex]\frac{Adjacent}{Hypotenuse}[/tex] )
1.) Find the Hypotenuse and the Adjacent to cos 45°
[tex]cos=\frac{Adj}{Hypoth} = (\frac{1}{\sqrt{2} } )[/tex]
2.) Rationalize the fraction (as it has a radical in the denominator)
[tex]\frac{1}{\sqrt{2} } *(\frac{\sqrt{2} }{\sqrt{2} } )=\frac{\sqrt{2} }{2}[/tex]
Answer: frac{\sqrt{2} }{2}[/tex]= Cos (45°)
