Question

Evaluate : (i) cosec 82
sec 8°
(ii) sec 70° sin 20° + cos 20° cosec 70°​

Answer 1

Answer:

1. sec²8⁰

2. 2

Explanation:

1. cosec82⁰ sec8⁰ = 1/sin82⁰ sec8⁰

1/cos(90-82)⁰ sec8⁰

1/cos8⁰ sec8⁰

sec8⁰ (sec8⁰) = sec²(8⁰)

2. sec70⁰sin20⁰ + cos20⁰cosec70⁰

sec70⁰ [cos(90-20)] + sin(90-20) cosec70⁰

sec70⁰cos70⁰ + sin70⁰ cosec70⁰

sec70⁰ (1/sec70⁰) + sin70⁰ ( 1/sin70⁰)

1+1 = 2