Zol Tun Kul
Reputation
2,388
Top tag
Next privilege 2,500 Rep.
Create tag synonyms
 Nov 9 asked Help understand related rates problem: calculating the derivative of the distance function Nov 8 accepted Find the equations to the normal lines of a curve where $x = 4$. Nov 8 comment Find the equations to the normal lines of a curve where $x = 4$. Oh! Right! The normal line. I got it now. Thank you! Nov 8 comment Find the equations to the normal lines of a curve where $x = 4$. I see. $\frac{5}{10}$ would be the slope for a tangent line that passes by $(4,3)$. The tangent line equation would be $$y-3=\frac{5}{10}(x-4)$$ Which is $$y=\frac{x}{2}+1$$ It concerns me, because apparently the answer should be $$y=-2x+11$$ According to my book. Nov 8 comment Find the equations to the normal lines of a curve where $x = 4$. I have calculated the implicit derivative to be $$\frac{2x-y}{2y+x}$$ So the slopes of the tangent lines at $x = 4$ should be obtained by evaluating $x=4$ in this derivative, rather than the original function $y^2+4y-16=5$, no? If I plug $x=4$ in this derivative, I would get that $y=0$. Nov 8 comment Find the equations to the normal lines of a curve where $x = 4$. @G-man I mean getting the derivative of $y^2+4y-16=5$. I assumed that you could calculate derivatives of functions only. Nov 8 comment Find the equations to the normal lines of a curve where $x = 4$. @G-man ah, well, I didn't know that. So this curve is not a function? Does that mean I can't derive it? (I was guessing deriving it would be part of the solution or something like that) Nov 8 asked Find the equations to the normal lines of a curve where $x = 4$. Nov 8 accepted Finding the equation of the tangent line for the curve $f(x)=x^2+\frac{2}{x}$ parallel to $3y-2x=5$ Nov 8 asked Finding the equation of the tangent line for the curve $f(x)=x^2+\frac{2}{x}$ parallel to $3y-2x=5$ Nov 6 accepted Calculating the derivative of $\csc^2(4x)$ Nov 6 asked Calculating the derivative of $\csc^2(4x)$ Nov 6 revised Calculating a simpler derivative for $\frac{1+\cot x}{2- \sec x}$ added 3 characters in body Nov 6 asked Calculating a simpler derivative for $\frac{1+\cot x}{2- \sec x}$ Nov 3 comment Calculate the derivative of the product of three functions $e^x\cdot \ln(x) \cdot \cot x$ @Kaster that looks pretty cool - how did you reach that conclusion? Nov 3 asked Calculate the derivative of the product of three functions $e^x\cdot \ln(x) \cdot \cot x$ Nov 3 accepted The derivative of $-e^{\sqrt{2}\cdot x}\cdot 5x^3$ Nov 3 asked The derivative of $-e^{\sqrt{2}\cdot x}\cdot 5x^3$ Oct 29 awarded Notable Question Oct 13 accepted Differentiating $\sqrt{x}+\sqrt{x^3}+\sqrt[3]{x^2}$