use definite integral to find area under the curve between the x-vales with a sketch of the curve showing the region.  f(x)= 4-x from x=0 to x=4

aruv | Student

Area of the triangle between  axes and red line

`A=int_0^4f(x)dx`

`=int_0^4(4-x)dx`

`=(4x-x^2/2)}_0^4`

`=(16-16/2)-(0-0/2)`

`=8 sq. unit`