If sin 3A = cos(A - 26°), where 3A is an acute angle then the value of A is?

Solution (By Examveda Team)

$$\eqalign{ & \Rightarrow {\text{sin 3A}} = {\text{cos}}\left( {{\text{A}} - {{26}^ \circ }} \right) \cr & \Rightarrow {\text{3A + A}} - {\text{2}}{{\text{6}}^ \circ }{\text{ = }}{90^ \circ } \cr & \left[ {{\text{If sin A}} = {\text{cos B}}{\text{. then, A}} + {\text{B}} = {{90}^ \circ }} \right] \cr & \Rightarrow 4{\text{A = 11}}{6^ \circ } \cr & \Rightarrow {\text{A}} = {29^ \circ } \cr} $$