What is the limit of sin(2x)/x^2 as x approaches 0?

1 Answer
Dec 11, 2014

lim_{x to 0}{sin(2x)}/{x^2}

by l'Hhat{"o"}pital's Rule (0/0),

=lim_{x to 0}{2cos(2x)}/{2x}=lim_{x to 0}{cos(2x)}/{x}

Since

{(lim_{x to 0^-}{cos(2x)}/x=1/0^{-} = -infty),(lim_{x to 0^{+}}{cos(2x)}/x=1/0^{+}=+infty):},

lim_{x to 0}{cos(2x)}/x does not exist,

which means that

lim_{x to 0}{sin(2x)}/{x^2} does not exist.

Let us look at the graph of y={sin(2x)}/x^2.

enter image source here

The graph above indeed agrees with our conclusion.


I hope that this was helpful.