if secA=cosecB=15/7,then A+B is equal to__________
 
 
a)zero   b)90    c)<90    d)>90

Asked by pugalatha | 12th Sep, 2015, 11:47: PM

Expert Answer:

G i v e n space t h a t space s e c A equals cos e c B equals 15 over 7 rightwards double arrow fraction numerator H y p o t e n u s e over denominator a d j a c e n t space o f space A end fraction equals 15 over 7 space a n d space fraction numerator H y p o t e n u s e over denominator O p p o s i t e space o f space B end fraction equals 15 over 7 rightwards double arrow H y p o t e n u s e equals 15 k comma space A d j a c c e n t space o f space a n g l e space A equals 7 k comma space w h e r e space k space i s space a n y space c o n s tan t. B y space a p p l y i n g space P y t h a g o r a s space T h e o r e m comma space w e space h a v e comma open parentheses 15 k squared close parentheses equals open parentheses 7 k close parentheses squared plus open parentheses O p p o s i t e space o f space a n g l e space A close parentheses squared rightwards double arrow A B C space i s space a space r i g h t space t r i a n g l e comma space r i g h t space a n g l e d space a t space C rightwards double arrow angle A plus angle B equals 90 degree H e n c e space t h e space c o r r e c t space o p t i o n space i s space left parenthesis b right parenthesis.

Answered by Vimala Ramamurthy | 13th Sep, 2015, 02:23: PM

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