Q10 of 73 Page 458

The two adjacent sides of a parallelogram are and . Find the unit vector parallel to its diagonal. Also, find its area.

Given: Two adjacent sides of a parallelogram are


Then the diagonal of parallelogram is given by the resultant of .


Let the diagonal is .


Then





Then





∴ unit vector parallel to its diagonal is


And area of parallelogram ABCD is






∴


Hence, area of parallelogram ABCD is .


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