What is the derivative of #sin (x/2)#?

1 Answer
Jul 13, 2016

#1/2cos(x/2)#

Explanation:

Differentiate using the #color(blue)"chain rule"#

#color(red)(|bar(ul(color(white)(a/a)color(black)(d/dx(f(g(x)))=f'(g(x))g'(x))color(white)(a/a)|))) ........ (A)#

#f(g(x))=sin(x/2)rArrf'(g(x))=cos(x/2)#

and #g(x)=x/2=1/2xrArrg'(x)=1/2#
#"------------------------------------------------------"#
Substitute rhese values into (A)

#rArrf'(g(x))=cos(x/2)xx1/2=1/2cos(x/2)#