Home » Aptitude » Trigonometry » Question
  1. If tan (5x – 10°) = cot (5y + 20°), then the value of (x + y) is
    1. 15°
    2. 16°
    3. 22
      2

    4. 24°
Correct Option: B

tan (90° – θ) = cotθ
∴ tan (5x – 10°) = cot (5y + 20°)
⇒ tan (5x – 10°) = tan {90° – (5y + 20°)}
⇒ 5x – 10° = 90° – (5y + 20°)
⇒ 5x – 10° = 90° – 5y – 20°
⇒ 5x + 5y = 70° + 10°
⇒ 5 (x + y) = 80°

⇒ x + y =
80°
= 16°
5



Your comments will be displayed only after manual approval.