Let f(x)= 3x

a. sketch the region R under the graph of f on the interval [0,2] and find its exact area using geometry.

The book says the answer is 6, but I have no idea how the steps needed to solve for the area.

Thanks for the help

It just forms a triangle with base length 2 along the x-axis and height 6. You can check your answer by just using the formula for the area of a triangle.

It is a line with slope 3 passing through the origin. Graph it and see.


To find the area by integrating

Do it the easy way and by integrating. You should get the same solution.