Main formula cos (a - b) =cosacosb + sina sinb
arccos(-x) = pi -arccosx
<span>cos x cos (pi/7)+sin x sin(pi/7) = cos(x-pi/7)
so </span>cos(x-pi/7) = -(sqrt 2)/2, x -pi/7 = arc cos[-(sqrt 2)/2 ]= pi - arc cos[(sqrt 2)/2<span> ]
</span>arc cos[(sqrt 2)/2 ] = Pi/4 + 2kpi, and then x -pi/7 = pi - pi/4 +2kpi,
implies x= -pi/7 + pi - pi/4 = -<span>pi/7 + 3pi/4 = -19pi/28 + 2kpi</span>
33.44 will be the answer rounded to the nearest hundredth.
Answer:
s = -15
Step-by-step explanation:
-12 + (-18) = -30
-30= 2s
-15 = s
Answer:
they are similar by aa.
Step-by-step explanation:
if you plug in the 109 and add the 30 and 41, they equal 180