InterviewSolution
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InterviewSolution
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Statement -1: `sin52^(@)+sin78^(@)+sin50^(@)=4cos26^(@)cos39^(@)cos25^(@)` Statement-2: If `A+B+C=pi, then sinA+sin B+sinC=4cos""(A)/(2)cos""(B)/(2)cos""©/(2)`A. Statement-1 is True, Statement-2 is true, Statement-2 is a correct explanation for Statement -1.B. Statement-1 is True, Statement-2 is True, Statement-2 is not a correct explanation for Statement-1.C. Statement-1 is True, Statement-2 is False.D. Statement-1 is False, Statement-2 is True. |
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Answer» Correct Answer - A If `A+B+C=pi, then sinA+sinB+sinC` `=2sin""(A+B)/(2)cos""(A-B)/(2)+2sin""(C)/(2)cos""(C)/(2)` `=2cos""(C)/(2){cos""(A-B)/(2)+cos""(A+B)/(2)}=4cos""(A)/(2)cos""(B)/(2)cos""(C)/(2)` So, statement-2 is true. On replacing A by `52^(@),Bby78^(@)and C by 50^(@),` we obtain statement-1. Hence, both the statements are true and statement-2 is a correct explanation for statement-1. |
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