Q.In triangle ABC, angle B is a right angle. The hypotenuse is \(\sqrt{15}\), and the sum of the other two sides is 4. What is the value of \((\cos A + \cos C)\)? (a) \(\cfrac{8}{\sqrt{13}}\) (b) \(\cfrac{-8}{\sqrt{15}}\) (c) \(\cfrac{-8}{\sqrt{13}}\) (d) \(\cfrac{8}{\sqrt{15}}\)
Answer: D
\((\cos A + \cos C)\) \(= \frac{AB}{AC} + \frac{BC}{AC}\) \(= \frac{AB + BC}{AC}\) \(= \frac{8}{\sqrt{15}}\) So, the value of \((\cos A + \cos C)\) is \(\frac{8}{\sqrt{15}}\).
Similar Questions