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Question
Prove that: `sin^2 pi/6 + cos^2 pi/3 - tan^2 pi/4 = -1/2`
Solution
Left side = `sin^2 pi/6 + cos^2 pi/3 - tan^2 π/4`
= `(1/2)^2 + (1/2)^2` - 12
(∵ sin `π/6 = 1/2 , cos π/3 = 1/2 , tan pi/4` = 1)
= `1/4+1/4-1=1/2` Right side.
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