cot 54°/tan 36° + tan 20°/cot 70° – 2 = 0

(i) cot 54°/tan 36° + tan 20°/cot 70° – 2 = 0

(ii) sin 50°/cos 40° + cosec 40°/sec 50° – 4 cos 50° cosec 40° + 2 = 0.

Answer :

(i) cot 54°/tan 36° + tan 20°/cot 70° – 2 = 0

LHS = cot 54°/tan 36° + tan 20°/cot 70° – 2

= cot 54°/tan (90° – 54°) + tan 20°/cot (90° – 20°) – 2

= cot 54°/ cot 54° + tan 20°/ tan 20° – 2

= 1 + 1 – 2

= 0

= RHS

(ii) sin 50°/cos 40° + cosec 40°/sec 50° – 4 cos 50° cosec 40° + 2 = 0

LHS = sin 50°/cos 40° + cosec 40°/sec 50° – 4 cos 50° cosec 40° + 2

= sin 50°/cos (90° – 50°) + cosec 40°/sec (90° – 40°) – 4 cos 50° cosec (90° – 50°) + 2

= sin 50°/sin 50° + cosec 40°/cosec 40° – cos 50° sec 50° + 2

= 1 + 1 – (4 cos50°/cos 50°) + 2

= 1 + 1 – 4 + 2

= 4 – 4

= 0

= RHS

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