Question

4 cos 0 cos 3 + 0 cos 3 - 0 = cos 30 s = sin 5x sin

Answer 1

Answer:

Step-by-step explanation:

arccos  = cos⁻¹  = 90° 0' 0"

= 90° + k×360°  (k=..-1,0,1,..)

= -270°, 90°, 450°, ..

= 1.57079633rad + k×2π  (k=..-1,0,1,..)

= -1.5π, 0.5π, 2.5π,