This is the basic and conceptual question from trigonometric ratios in which we have been asked to show that
(i) sinAcosC+cosAsinC = 1
(ii) cosAcosC−sinAsinC = 0
If in a ΔABC, angle B =90° and tanA =1/√3.
RS Aggarwal, Class 10, chapter 10, question no 29.
Hope it helps you.