How do you evaluate the definite integral by the limit definition given #int (1-absx)dx# from [-1,1]?

1 Answer
Feb 24, 2017

# int_(-1)^(-1) \ 1-|x| \ dx = 1 #

Explanation:

This is a graph of the function:
graph{1-|x| [-2.52, 2.48, -0.91, 1.59]}

As a define integral represents the area under the graph of the function, then simply be elementary geometry, the area is two triangles (or a square); hence without any calculation;

# int_(-1)^(-1) \ 1-|x| \ dx = 1 #

I will leave it to someone else to evaluate using the limit definition, but essentially it will be a limit derivation of the area of a triangle.