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Q: The value of sin²20⁰ + sin²70⁰ – tan²45⁰ + sec60⁰ is equal to: sin²20⁰ + sin²70⁰ – tan²45⁰ + sec60⁰ का मान किसके बराबर है?
  • A. 2
  • B. 2.5
  • C. 1
  • D. 3
Correct Answer: Option A - sin²20⁰ + sin²70⁰ – tan²45⁰ + sec60⁰ = sin²20⁰ + sin²(90⁰–20⁰) – (1)² + 2 = (sin² 20⁰ + cos² 20⁰) – 1 + 2 = 1 – 1 + 2 = 2
A. sin²20⁰ + sin²70⁰ – tan²45⁰ + sec60⁰ = sin²20⁰ + sin²(90⁰–20⁰) – (1)² + 2 = (sin² 20⁰ + cos² 20⁰) – 1 + 2 = 1 – 1 + 2 = 2

Explanations:

sin²20⁰ + sin²70⁰ – tan²45⁰ + sec60⁰ = sin²20⁰ + sin²(90⁰–20⁰) – (1)² + 2 = (sin² 20⁰ + cos² 20⁰) – 1 + 2 = 1 – 1 + 2 = 2