Question

Write the expression as either the sine, cosine, or tangent of a single angle.
sin ( pi / 2 ) * cos( pi / 7 ) + cos ( pi / 2 ) * sin (pi/ 7)

Answer 1

This is the result of a sum of sines formula. This is what you get when you have sin(a + b). So just take what you have and put it backwards into the sum of sines sin(a + b)

Answer 2

So add pi over 2 and pi over 7 together

Answer 3

Pretty much xD

Answer 4

Alright but first would I cross multiply them

Answer 5

Nope, it's just
\[\sin(\frac{ \pi }{ 2 }+\frac{ \pi }{ 7 })\]

Answer 6

Ok so it would be \[\sin ( \frac{ \pi }{ 9 } )\]

Answer 7

Well, we need to add the fractions like normal, common denominators and things like that.

Answer 8

Alright would it be \[\sin ( 2 \pi / 9 ) \] then

Answer 9

Hmm
\[\frac{ \pi }{ 2 }*\frac{ 7 }{ 7 } + \frac{ \pi }{ 7 }*\frac{ 2 }{ 2 }\]
\[\frac{ 7\pi }{ 14 }+ \frac{ 2\pi }{ 14 } = \frac{ 9\pi }{ 14 }\]
Kinda see how?

Answer 10

yeah and this would be a sin expression

Answer 11

Yeah, itd be sin(9pi/14) and that would be your answer.

Answer 12

Ok thanks

Answer 13

Mhm.