A 10 inches long pencil A B with mid point C and a small eraser P are placed on the horizontal top of a table such that P C = 5 inches and ∠ P C B = tan - 1 ( 2 ) . The acute angle through which the pencil must be rotated about C so that the perpendicular distance between eraser and pencil…

Question

A 10 inches long pencil A B with mid point C and a small eraser P are placed on the horizontal top of a table such that P C = 5 inches and &#8736; P C B = tan - 1 ( 2 ) . The acute angle through which the pencil must be rotated about C so that the perpendicular distance between eraser and pencil becomes exactly 1 inch is :

Aicharya · Accepted Answer

From figure, sin &#946; = 1 5 tan &#946; = 1 2 tan ( &#945; + &#946; ) = 2 tan &#945; + &#946; = tan &#945; + 1 2 1 - tan &#945; &#160; . 1 2 = 2 &#945; = tan - 1 3 4

A 10 inches long pencil A B with mid point C and a small eraser P are placed on the horizontal top of a…

Solution