- #1
Wm_Davies
- 51
- 0
Homework Statement
Let
[tex]\int_{-4}^{2} f(x) dx =9, \int_{-4}^{-2} f(x) dx=2, \int_{0}^{2} f(x)dx =3[/tex]
Find (I have solved this one)
[tex]\int_{-2}^{0} f(x)dx= 4[/tex]
Find
[tex]\int_{0}^{-2} (9 f(x)- 2)dx= ?[/tex]
Homework Equations
[tex]\int_{a}^{b} f(x) dx = F(b) - F(a)[/tex]
The Attempt at a Solution
I don't see where I am doing something wrong.
[tex]\int_{0}^{-2} (9 f(x)- 2)dx[/tex]
[tex]-\int_{-2}^{0} (9 f(x)- 2)dx[/tex]
Using the fundamental theorem of calculus.
b=0
a=-2
-[(9b(4) - 2b) - (9a(4) - 2a)]
-[(0(4) - 0) - (9(-2)(4) - 2(-2))]
Solving for that I get
-[-(-72+4)]
-[-(-68)]
Therfore I figure that
[tex]\int_{0}^{-2} (9 f(x)- 2)dx= -68[/tex]
However the electronic homework says it is incorrect, but why?