- #1
lionely
- 576
- 2
Homework Statement
Find the areas enclosed by the following curves and straight lines:
c) y= (1/x2) -1 , y= -1 , x=1/2, and x=2
b) y = x3-1, the axes and y = 26
2. The attempt at a solution
Okay I sketched the curve and to me it looks like the curve occupies no area at y=-1 it's undefined there.
so isn't the area occupied from x = 1/2 to x =2
so ∫1/x2) -1 . dx
y= [(1/x) - x ] + c
( (1/2) - 2) - ( 2 - (1/2)) = -3
but the answer in my book says 3/2
and for the 2nd question
The points at which these curves intersect are (3,26)
∫x3 -1 . dx
y = (x4/4) - x = 17 1/4 ( x = 0 to 3)
∫26.dx = 26x = 78 sq units( from x 0 to 3)
78- 17/4 = 60 3/4 but in the back of my book it says 60 exactly, and I don't see what I did wrong..
Help is greatly appreciated~!