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Question:

Evaluate the following:
(i) sin 60° cos 30° + sin 360° cos 60°
(ii) 2tan²45° + cos²30° - sin²60°
(iii) cos 45° sec 30° + cosec 30°
(iv) sin 30° + tan 45° - cosec 60° sec 30° + cos 60° + cot 45°
(v) 5cos²60° + 4sec²30° - tan²45 sin²30° + cos²30°

Solution:

(i) sin 60° cos 30° + sin 360° cos 60° = (√3/2)(√3/2) + 0(1/2) = 3/4 + 0 = 3/4
(ii) 2tan²45° + cos²30° - sin²60° = 2(1)² + (√3/2)² - (√3/2)² = 2 + 3/4 - 3/4 = 2
(iii) cos 45° sec 30° + cosec 30° = (1/√2)(2/√3) + 2 = √2/√3 + 2 = √6/3 + 2 = (2√6 + 6)/3
(iv) sin 30° + tan 45° - cosec 60° sec 30° + cos 60° + cot 45° = 1/2 + 1 - (2/√3)(2/√3) + 1/2 + 1 = 1/2 + 1 - 4/3 + 1/2 + 1 = 3 - 4/3 = 5/3
(v) 5cos²60° + 4sec²30° - tan²45 sin²30° + cos²30° = 5(1/2)² + 4(2/√3)² - (1)²(1/2)² + (√3/2)² = 5/4 + 16/3 - 1/4 + 3/4 = 5/4 - 1/4 + 3/4 + 16/3 = 7/4 + 16/3 = (21 + 64)/12 = 85/12