HW Supplement: Equation of Tangent Line Namt Let
f(x)=0.1x^(3)-2.5x+3.4
a). Use a graphing tool to graph of
f(x)
for the window
x[-6,6]
and
y[-5,10]
and find
f(0),f(6)
, and
f(4)
. Then plot and label the three points and reproduce a sketch of the graph below. b. Use a ruler to sketch, above, the secant line between the points where
x=0
and
x=6
. The slope of this secant line is the AVERAGE rate of change of
f(x)
over the interval
0,6
. c. Find the average rate of change of
f(x)
over the interval
0,6
. (show work). d. Use a ruler to sketch, above, the tangent line to
f(x)
at the point where
x=4
. e. Is the slope of the tangent line greater or less than the slope of the secant line drawn? (guess) f. Use the basic rules to find
f^(')(x)
.
f(x)=0.1x^(3)-2.5x+3.4,f^(')(x)=
The instantaneous rate of change of
f
at
x=4
is the slope of the tangent line at that point. The slope of the tangent to a function at a point is the derivative at that point. g. Find
f^(')(4)=
and compare this slope to the slope of the secant from (c). h. Use your results in part
g
to find the equation of the tangent line to
f(x)
at
x=4
. Pt:
(4,f(4))
Slope:
m=f^(')(4)
Equation of line:
y-y_(o)=m(x-x_(o))