MATH110/April 2017/Question 11 (b)

Again, since MATH 110 students has slightly week background on pre-calculus, it would be helpful for students if you explain the range of $\sin x$ on (0,\frac{\pi}{2}).

Also, when you put fraction inside of the bracket, please use \left( and \right).

Thanks!

p.s., please change the flags to R after you revised!

It would be great, if you recall from part (a) that c lies on (0,pi/2) :)

I made some changes... but not sure about whether I need to further explain why \sin x is positive on this interval.

Thanks, Aili. No you don't need to explain further, because they learn about trigonometric function in the class.