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A circular ring of radius 3 cm is suspended horizontally from a point 4 cm vertically above the centre by 4 strings attached at equal intervals to its cirumference . If the angle between two consecutive strings be theta,then cos 0- |
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Answer» `4/5` `therefore angleAOB=90^@` Also, in `triangleAOP`, we have `AP=sqrt(OA^2+OP^2)=sqrt(3^2+4^2)=5` `rArr` BP=AP=5 In `triangleAPB` , we have `cos THETA=(AP^2 +BP^2 -AB^2)/(2 AP.BP)` `rArr cos theta=(5^2+5^2 -(3sqrt2)^2)/(2xx5xx5)[ "In" triangleAOB, AB^2=OA^2+OB^2]` `rArr cos theta=16/25` |
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