Please see the answer here
http://www.wolframalpha.com/input/?i=y%5E-1%20dy%20%2Bye%5E%28cosx%29%20sinxdx%3D0
Let
The origin of coordinates the tree
r1 = vector position of the child 1.
r2 = vector position of the child 2
Child 1:
r1 = (12i + 12j)
Child 2:
r2 = (-18i + 11j)
The scalar product will be given by:
r1.r2 = ((12) * (- 18)) + ((12) * (11)) = - 84
The scalar product of their net displacements from the tree is -84m ^ 2
The area of a triangle for one of the legs being 3 inches and the hypotenuse being 9 inches is 12.727 square inches
<em><u>Solution:</u></em>
Given that to find area of a triangle for one of the legs being 3 inches and the hypotenuse being 9 inches
From given information,
Let "c" = hypotenuse = 9 inches
Let "a" = length of one of the leg of triangle = 3 inches
To find: area of triangle
<u><em>The area of triangle when hypotenuse and length of one side of triangle is given:</em></u>

Where, "c" is the length of hypotenuse
"a" is the length of one side of triangle
Substituting the given values we get,


Thus area of triangle is 12.727 square inches