MHB Slope of polar curve at indicated point

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The discussion focuses on calculating the slope of a polar curve at the point defined by $r=5$ and $\theta=\pi/6$. The formula for the slope is correctly stated, involving derivatives with respect to $\theta$. A participant confirms the formula's validity but questions whether $r$ is a function of $\theta$. The calculation presented yields a slope of $-\frac{\sqrt{3}}{3}$, but there is a suggestion to ensure the angle used is $\frac{\pi}{6}$. The conversation emphasizes the importance of correctly applying the polar slope formula.
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$r=5$ and $\theta=\pi/6$$\frac{dy}{dx}=\frac{\frac{dy}{d \theta}}{\frac{dx}{d \theta}}=\frac{\frac{dr}{d \theta}sin(\theta)+rcos(\theta)}{\frac{dr}{d \theta}cos(\theta)-rsin(\theta)}$

$\frac{0*sin(\pi/3)+5cos(\pi/3)}{0*cos(\pi/3)-5sin(\pi/3)}=-\frac{\sqrt{3}}{3}$is that right?
 
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i think i did everything right. that's the slope equation in my book so i just plugged everything in.
 
There are probably loads of proofs of this online, but I do not want to cheat. Here is my attempt: Convexity says that $$f(\lambda a + (1-\lambda)b) \leq \lambda f(a) + (1-\lambda) f(b)$$ $$f(b + \lambda(a-b)) \leq f(b) + \lambda (f(a) - f(b))$$ We know from the intermediate value theorem that there exists a ##c \in (b,a)## such that $$\frac{f(a) - f(b)}{a-b} = f'(c).$$ Hence $$f(b + \lambda(a-b)) \leq f(b) + \lambda (a - b) f'(c))$$ $$\frac{f(b + \lambda(a-b)) - f(b)}{\lambda(a-b)}...

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