For the function

MATHEMATICS · Single correct · AP · Calculus AB · Analytical Applications of Differentiation · Analytical Applications of Differentiation

Problem

For the function

f(x)=\ln x-\cos x

, at which of the following values of

x

does the graph of

f

have a horizontal tangent line? (a)

x\approx2.09

(b)

x\approx3.45

(c)

x\approx1.57

(d)

x\approx1.12