Mathematics

Problem

Which of the following limits equals

1

? a)

\displaystyle \lim_{x\to 0} \frac{1-\cos(7x)}{x^{2}}

\displaystyle \lim_{x\to 0} \frac{1-\cos(7x)}{x}

\displaystyle \lim_{x\to 0} \frac{\sin(7x)}{7x}

\displaystyle \lim_{x\to 0} \frac{\sin(7x)}{x}