Question

If $y=\sin x^o+\cos x^o$, find $\frac{dy}{dx}$

Answer 1

${180}^{\circ }=\pi$rads

$1^{\circ }=\frac{\pi }{180}$rads

$x^{\circ }=\frac{\pi x}{180}$rads

$\therefore y=\sin \frac{\pi x}{180}+\cos \frac{\pi x}{180}$

$\frac{dy}{dx}=\frac{\pi }{180}\cos \frac{\pi x}{180}-\frac{\pi }{180}\sin \frac{\pi x}{180}$

$=\frac{\pi }{180}(\cos \frac{\pi x}{180}-\sin \frac{\pi x}{180})$

$\therefore \frac{dy}{dx}=\frac{\pi }{180}(\cos x^{\circ }-\sin x^{\circ })$