Вычислить   sin13π/6 - cos11π/6 +ctg11π/4

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sin13π/6 - cos11π/6 +ctg11π/4 =sin(2π+π/6)-cos (2π-π/6) +ctg(3π -π/4)

= sin(π/6) - cos (π/6)  - ctg(π/4) = 1/2 -√3 /2 - 1 = - (√3 +1) /2

* * * ctg11π/4 = ctg(2π+(π -π/4) )  =tg(π - π/4) = - ctgπ/4 =  -1  * * *

Verified answer

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