OllieMoo
contestada

Write the expression as either the sine, cosine, or tangent of a single angle.

sine of pi divided by two times cosine of pi divided by seven plus cosine of pi divided by two times sine of pi divided by seven.

Relax

Respuesta :

Note that
sin(x + y) = sin(x) cos(y) + cos(x) sin(y).

Therefore by setting x = π/2 and y = π/7, obtain
sin(π/2 + π/7) = sin(π/2)*cos(π/7) + cos(π/2)*sin(π/7)

The right side is what we want to evaluate.  It is equal to
sin(π/2 + π/7) = sin (9/14)π

Answer:  [tex]sin( \frac{9 \pi }{14}) [/tex]