Do you know how to do this problem?
cos (13π12)
cos
1 Answer
Apr 23, 2018
Formula:-
(1) cos(π+θ)=−cosθ
(2) cos2θ=2cos2θ−1 Problem:-
↓
cos(13π12)
=cos(π+π12)
=−cos(π12)
=− ⎷1+cos(π6)2
=−√1+√322
=−√12+√34
=−14√8+4√3
=−14√(√6+√2)2
=−14(√6+√2) Hope this helps...
Thank you...
:-)
