Concept:The slope of the tangent to a curve is given by its derivative. To find the minimum slope, we differentiate the slope function and set its derivative to zero.
Explanation:The curve is
y=x3−3x2+2x+93.
Differentiate
y with respect to
x to get the slope
T:
T=dxdy=3x2−6x+2Now find
dxdT to locate the critical point:
dxdT=6x−6Set
dxdT=0:
6x−6=0⇒x=1Check that this is a minimum by finding
dx2d2T:
dx2d2T=6>0Since the second derivative is positive,
x=1 gives the minimum slope.
Substitute
x=1 into
T:
T=3(1)2−6(1)+2=3−6+2=−1Therefore, the minimum value of the slope is
−1.
Answer:The minimum value of the slope is
−1, which corresponds to option B.