Question

plzz solve it step wise

Answer 1

We know thatcos (-x) = $\pi - cos (x)$
so, cos(-√3/2) = $\pi - cos \sqrt{3}/2$                         = pi - pi/6
Now, put it in the Question LHS,
= cos ( pi/6 + pi - pi/6)= cos ( pi)= -1 = RHS
Hence Proved.

Answer 2

$Given : cos( \frac{ \pi }{6} + cos^{-1} (- \frac{ \sqrt{3} }{2} ))$

$= \ \textgreater \ cos( \frac{ \pi }{6} + \frac{5 \pi }{6} )$

$= \ \textgreater \ cos( \frac{6 \pi }{6} )$

$= \ \textgreater \ cos( \pi )$

-1.


Hope this helps!