In triangle ABC, right-angled at B, if find the value of:

(i) Sin A Cos C + Cos A Sin C


(ii) Cos A Cos C – Sin A Sin C


tan A = =

If BC is k, then AB will be, where k is a positive integer


In ΔABC,


AC2 = AB2 + BC2


= ()2 + (k)2


= 3k2 + k2 = 4k2


AC = 2k


Sin A =


= =


Cos A =


= =


Sin C =


= =


Cos C =


= =


(i) sin A cos C + cos A sin C


= ( () + (


=


=


(ii) cos A cos C - sin A sin C


= () () – () ()


=


= 0


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