The Solution to Question 25:
Given:
[tex]sec135^o[/tex]
We are required to evaluate the given expression.
[tex]sec135^o=\frac{1}{\cos135^o}[/tex]
Recall:
[tex]\cos135^o=-\cos(180-135)=-\cos45^o=-\frac{\sqrt{2}}{2}[/tex]
Thus,
[tex]sec135^o=\frac{1}{cos135^o}=\frac{1}{-\frac{1}{\sqrt{2}}}=-\frac{\sqrt{2}}{1}=-\sqrt{2}[/tex]
Therefore, the correct answer is:
[tex]-\sqrt{2}[/tex]
