## About the convexity of sinx\sin x for π≤x≤2π\pi\leq x\leq 2\pi [closed]

Closed. This question is off-topic. It is not currently accepting answers. Want to improve this question? Update the question so it’s on-topic for Mathematics Stack Exchange. Closed 6 years ago. Improve this question To prove the convexity of sinx over [π,2π] through the second derivative is easy, but I would be interested in a (possibly) … Read more

## How to find if a point is outside a circle circumference area?

I’d like to know if it’s possible to calculate if a point is inside or outside the circle circumference area based on it’s $x$ and $y$ values ? Example, $(x, y)= (0.85, -0.9)$ and the radius is $1$ Answer You need only calculate the distance between $(x_1, y_1)$ (the point in question) and $(x_0, y_0)$ … Read more

## Question based on triangle inscribed in unit circle

△ABCis inscribed in a unit circle.If angle bisectors of internal angles at A,B and C meet the circle at D,E and F respectively then value of ADcosA2+BEcosB2+CFcosC2sinA+sinB+sinCis ? My attempt:AD,BE,CF are angle bisectors,so they meet at incenter of triangle but i dont know whether this incenter will be the center of unit circle or not.If … Read more