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Question
Evaluate:
`(tan 65^circ)/(cot 25^circ)`
Solution
`(tan 65^circ)/(cot 25^circ)`
= `tan(90^circ - 25^circ)/cot 25^circ` (∵ `tan(90^circ - theta) = cot theta)`
= `cot 25^circ/cot 25^circ`
= 1
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Activity:
`square` = 1 + tan2θ ......[Fundamental trigonometric identity]
`square` – tan2θ = 1
(sec θ + tan θ) . (sec θ – tan θ) = `square`
`sqrt(3)*(sectheta - tan theta)` = 1
(sec θ – tan θ) = `square`
