Mathematics

Problem

Which of the following limits, if it exists, equals the slope of the line tangent to the graph of

y=\sqrt{x}

x=4

? a)

\displaystyle \lim_{x\to 4}\frac{\sqrt{x}-\sqrt{4}}{x+4}

\displaystyle \lim_{h\to 0}\frac{\sqrt{4+h}-\sqrt{4}}{h}

\displaystyle \lim_{h\to 0}\frac{\sqrt{4+h}-\sqrt{4}}{4+h}

\displaystyle \lim_{x\to 4}\frac{\sqrt{x}-\sqrt{4}}{(x-4)^{2}}