Does the function satisfy the hypotheses of the Mean Value Theorem on the given interval if #f(x) = 2x^2 − 3x + 1# and [0, 2]?

1 Answer
Apr 2, 2015

The Mean Value Theorem says that
if a function #f(x#) is differentiable over a range #[x_1,x_2]#
then there exists a value #c# within the range #[x_1,x_2]# such that

#f'(c) = (f(x_2) - (f(x_1)))/(x_2-x_1)#
(The right hand side of this is often referred to as the secant).

For the given function
#f(x) = 2x^2-3x+1# using #x_1=0# and #x_2=2#

#(f(2) - f(0))/(2-0)#

#=3/2#

#f'(x) = 4x-3#

If we (temporarily) assume the Mean Value Theorem holds then there must be a value #c# such that
#4c - 3 = 3/2#
which solves as
#c=9/8#

Testing this back in the equation of the Mean Value Theorem demonstrates that the theorem holds for the given equation.