COMEDK2025MathematicsTrigonometric Ratios & IdentitiesActual
The value of ^2 20^ + ^4 20^ ^4 20^ + ^2 20^ is
Options
- A2
- B0
- C1 2
- D1
Correct answer
D. 1
Step-by-step solution
Let = 20^ . The expression is E = ² + ⁴ ⁴ + ² . Using the identity ² = 1 - ² , we substitute into the numerator: Numerator = (1 - ² ) + ⁴ = 1 - ² + ⁴ . Using the identity ² = 1 - ² , we substitute into the denominator: Denominator = ⁴ + (1 - ² ) = 1 - ² + ⁴ . Since ² = 1 - ² , the numerator becomes 1 - (1 - ² ) + (1 - ² )² = 1 - 1 + ² + 1 - 2 ² + ⁴ = 1 - ² + ⁴ . Thus, the numerator is equal to the denominator, so E = 1 . Answer: 1