If I understood what you---and the problem #8--- mean, then,Originally Posted byfrozenflames

---your description of the graph does not tally with the figure as shown.

---the area under the graph from x=1 to x=3 is 2.3 sq.units.

---find the area under the graph from x=0 to x=3.

---the F'(x) = f(x) is beyond me.

Okay.

"INT.(1->3)[f(x)]dx" means the area under the graph of f(x) and above the x-axis from x=1 to x=3.

It means also F(3) minus F(1).

And it is equal to 2.3 sq.units as given.

So if we are to find F(3) minus F(0), which is the area under the graph of f(x) and above the x-axis from x=0 to x=3, then we just need to find the area under the graph from x=0 to x=1 and then add that to 2.3 sq.units.

Meaning,

F(3) -F(0) = {F(1) -F(0)} +{F(3) -F(1)}

F(3) -F(0) = {F(1) -F(0)} +2.3

F(3) -F(0) = {2*1} +2.3 -------------F(1) -F(0) is a rectangle that is 2units by 1unit.

F(3) -F(0) = 2 +2.3

F(3) -F(0) = 4.3 sq.units ----------answer.

Or, D from the multiple choice is the answer.

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Ooppss, you are in integration now?

Okay.

F(1) -F(0) = INT.(0->1)[f(x)]dx

Per the graph as shown,

f(x) = 2 -------------(a horizontal line at y=2.)

from x=0 to x=1,

So,

INT.(0->1)[f(x)]dx

= INT.(0->1)[2]dx

= [2x](0->1)

= 2(1) -2(0)

= 2 -0

= 2 sq.units.