River surveyors measured the speed of the current below a dam on the Columbia River in Washington. Based on their data, the speed (in feet per second) can be approximated by s(d) = -0.117d+1.68, where d is the depth (in feet) below the river's surface.
a. graph the given function
b. describe what happens to the speed of the current as you go deeper below the river's surface.
c. approximate the speed of the current at a depth of 9 feet.

Question

River surveyors measured the speed of the current below a dam on the Columbia River in Washington. Based on their data, the speed (in feet per second) can be approximated by s(d) = -0.117d+1.68, where d is the depth (in feet) below the river's surface. 
a. graph the given function 
b. describe what happens to the speed of the current as you go deeper below the river's surface.
c. approximate the speed of the current at a depth of 9 feet.