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If in a triangle ABC, sinA = cosB then the value of cosC is?
Answer & Solution
Correct Answer:
Option
B
$$\eqalign{
& {\text{In }}\vartriangle {\text{, }}\angle {\text{A + }}\angle {\text{B + }}\angle {\text{C}} = {\text{18}}{0^ \circ }\,....{\text{(i)}} \cr
& {\text{sin A}} = {\text{cos B}} \cr
& {\text{sin A}} = {\text{sin}}\left( {{{90}^ \circ } - {\text{B}}} \right){\text{ }} \cr
& {\text{A}} = {90^ \circ } - {\text{B}} \cr
& {\text{A}} + {\text{B}} = {90^ \circ }\,........(ii) \cr
& {\text{From equation (i) and (ii)}} \cr
& \angle {\text{C}} = {90^ \circ } \cr
& {\text{So, cos C }} = \cos {90^ \circ } = 0 \cr} $$
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