How do you find the exact value in radians without using a calculator #cos^-1 (1/2)#?

Question

8626 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2018-08-06T06:27:11

#cos^-1(1/2)=(pi/3)^R #

We know that ,

#color(red)((1)cos^-1(costheta)=theta ,where, theta in [0,pi]#

#(2)cos(pi/3)=1/2#

Using #(2)# ,we get

#cos^-1(1/2)=color(red)(cos^-1(cos(pi/3))# #and color(red)(pi/3 in[0,pi]#

#cos^-1(1/2)=color(red)(pi/3).....to[color(red)(apply (1))]#

Hence , #cos^-1(1/2)=pi/3 # # radians#