sinx - x multiplied by cosx - (pi/2)=0
please note, working in radians
any method to give the solution thats not an approximation
please email with any solutions
thanks
Well the method I propose uses routine algebra and recognition of special angles and values.
Using the null factor law (you might know it by a different name):
$\displaystyle \sin (x) - x = 0 \Rightarrow \sin x = x$ .... (1)
or
$\displaystyle \cos (x) - \frac{\pi}{2} = 0 \Rightarrow \cos x = \frac{\pi}{2}$ .... (2)
Regarding equation (1), an obvious exact solution is x = 0. The tricky bit is to show that this actually the only solution ......
Edit: Deleted my remarks on equation (2) for reasons made obvious by an ancient Greek philosopher!