User talk:Srmeier

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[edit] Problems

  • Please take the time to evaluate the questions before continuing on to the solutions.
  • There are only a few questions up at this time. I plan on add on to this list in the coming days.
  • If you have any questions please contact me.
  • (scroll past the problems to get the answers)



Problem #1:Find the Limit of the function.

\lim_{x \to \frac{\pi}{4}}\frac{\tan(x)-1}{x-\frac{\pi}{4}}



Problem #2:Find the derivative of the tangent function using the quotient rule.

\frac{d}{dx}\tan(x)= \frac{\sin(x)}{\cos(x)}



Problem #3:Find the slope of the tangent line at point P(4,.5).

f(x)= \frac{1}{\sqrt{x}}



Problem #4:Find the limit.

  • current problem (hint: think substitution and the limits of "e")

\lim_{x \to 0}\frac{\ln(1+2x)}{x}

[edit] Answers

Problem #1:This tests your knowledge of trig identities.


\lim_{x \to \frac{\pi}{4}}\frac{\tan(x)-\tan(\frac{\pi}{4})}{x-\frac{\pi}{4}}

\lim_{x \to \frac{\pi}{4}}\frac{\frac{\sin(x)}{\cos(x)}-\frac{\sin(\frac{\pi}{4})}{\cos(\frac{\pi}{4})}}{x-\frac{\pi}{4}}

\lim_{x \to \frac{\pi}{4}}\frac{\sin(x-\frac{\pi}{4})}{(x-\frac{\pi}{4})\cos(\frac{\pi}{4})\cos(x)} = \frac{1}{(\frac{\sqrt{2}}{2})(\frac{\sqrt{2}}{2})}= 2



Problem #2: This is very basic.


\frac{d}{dx}\tan(x)= \frac{\cos(x)\frac{d}{dx}\sin(x)-\sin(x)\frac{d}{dx}\cos(x)}{\cos^2(x)}

\frac{d}{dx}\tan(x)= \frac{\cos^2(x)+\sin^2(x)}{\cos^2(x)}

\frac{d}{dx}\tan(x)= \sec^2(x)



Problem #3:This is quite basic.


f ' (x) = \frac{ \sqrt{x}  - \sqrt{x+h} }{ h \sqrt{x} \sqrt{x+h} }

f'(x)= \frac{ -1 }{ 2 \sqrt{x^3} }