Question

Evaluate : 4 cot2 450

- sec2 600 + sin2 600 + cos2 900

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Answer 1

4 cot2 45°- sec2 60° + sin2 60° + cos2 90°

$= 4 \times (1)^{2} - (2)^{2} + ( \sqrt{3} \2) {}^{2} + (0) {}^{2} \\ = 4 - 4 +( 3 \4) + 0 \\ = 3 \4$