Chapter: Trigonometry· Mathematics Part 2 (Geometry)
Answer: \(\cos\theta = \dfrac{60}{61}\)
\(\sin^2\theta + \cos^2\theta = 1\)
\(\therefore \left(\dfrac{11}{61}\right)^2 + \cos^2\theta = 1\) \(\therefore \dfrac{121}{3721} + \cos^2\theta = 1\)
\(\therefore \cos^2\theta = 1 - \dfrac{121}{3721} = \dfrac{3600}{3721}\)
Taking square roots, \(\cos\theta = \dfrac{60}{61}\).