A function is defined by , .

MATHEMATICS · Multi-part · AP · AP Precalculus · Polynomial and Rational Functions · Polynomial and Rational Functions

Problem

A function

f

is defined by

f(x)=\frac{3}{x^2+2}

x\in\mathbb{R}

. (1) Sketch the curve

y=f(x)

, clearly indicating any asymptotes with their equations and stating the coordinates of any points of intersection with the axes. (2) The region

R

is bounded by the curve

y=f(x)

, the

x

-axis and the lines

x=0

and

x=\sqrt{6}

. Let

A

be the area of

R

. Show that

A=\frac{\sqrt{2}\pi}{2}

. (3) The line

x=k

divides

R

into two regions of equal area. Find the value of

k

. (4) Let

m

be the gradient of a tangent to the curve

y=f(x)

. Show that

m=-\frac{6x}{(x^2+2)^2}

. (5) Show that the maximum value of

m

\frac{27}{32}\sqrt{\frac{2}{3}}