Trignonometric Ratio of Some Specific Angle
- sudheer kumar kotha
Example : In a right triangle ABC, right-angled at AB, if tan A=1, then verify that 2 sin A Cos A = 1. Solution : In Δ ABC, tan A = BC/AB =1. BC= AB i.e., Let AB= BC= k, where k is a positive number. Now, AC = √AB²+BC² = √(k)²+(k)² = k√2 Therefore , sin A = BC/AC = 1/√2 and cos A = AB/AC= 1/√2 So, 2 sin A cos A = 2(1/√2)(1/√2) =1, which is the required value.