Given
To find the exact value of cos A.
Explanation:
It is given that,
[tex]\begin{gathered} opp.side=8 \\ adj.side=8 \\ hypotnuse=\sqrt{8^2+8^2} \\ =\sqrt{64+64} \\ =\sqrt{128} \\ =8\sqrt{2} \end{gathered}[/tex]That implies,
[tex]\begin{gathered} cosA=\frac{8}{8\sqrt{2}} \\ cosA=\frac{1}{\sqrt{2}} \end{gathered}[/tex]Hence, the exact value of cos A is,
[tex]\frac{1}{\sqrt{2}}[/tex]