Question 1194933
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(5)  tan(45°) = 1.   It is a table value,

                     which means that any/every/each student must know the answer from 
                     the table, without applying half-angle identity or any other identity.



(7)  sin(5π) = 0.   Every student must know it without applying half-angle identity or any other identity.




(8)  cos(30°) = {{{sqrt(3)/2}}}.   It is a table value,

                     which means that any/every/each student must know the answer from 
                     the table, without applying half-angle identity or any other identity.
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May I complete this post by joking ?


&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;To deduce / (to derive) the values of given angles using half-angle formulas 

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;is the same as to deduce multiplication table from the driving rules.