Answer:
A) cos(45) =[tex]\frac{1}{\sqrt{2}}[/tex].
Step-by-step explanation:
Given : A triangle 90 - 45-45 with perpendicular side 9.
To find : what is cos(45)?
Solution : We have given that triangle 90 - 45-45 with perpendicular side 9.
By the triangle 90 - 45-45 rule : adjacent side is same as opposite side and hypotenuse is √2 times of adjacent side.
Then adjacent side = 9
Hypotenuse = 9[tex]\sqrt{2}[/tex] .
Then cos(45) = [tex]\frac{adjacent side}{Hypotenuse}[/tex].
cos(45) = [tex]\frac{9}{9\sqrt{2}}[/tex]
cos(45) = [tex]\frac{1}{\sqrt{2}}[/tex]
Therefore, A) cos(45) = [tex]\frac{1}{\sqrt{2}}[/tex].
