How do you express $sin(pi/ 4 ) * sin( ( 9 pi) / 8 )$ without using products of trigonometric functions?

Question

How do you express $sin(pi/ 4 ) * sin( ( 9 pi) / 8 )$ without using products of trigonometric functions?

1 Answer

Impact of this question

1775 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2016-04-24T23:13:25

$-sqrt2/2sin (pi/8)$

Explanation:

$P = sin (pi/4)sin ((9pi)/8)$
Trig table --> $sin (pi/4) = sqrt2/2$
sin ((9pi)/8) = sin (pi/8 + pi) = -sin (pi/8)
Therefor, the product P can be expressed as:
$P = -(sqrt2/2)sin (pi/8)$
Note.
We can find P, by evaluation $sin (pi/8)$ , by using the trig identity:
$cos (pi/4) = sqrt2/2 = 1 - 2sin^2 (pi/8)$

Science

Math

Humanities

... and beyond

How do you express $sin(pi/ 4 ) * sin( ( 9 pi) / 8 )$ without using products of trigonometric functions?

1 Answer

Explanation:

Related questions

Impact of this question

Science

Math

Humanities

... and beyond

How do you express sin(pi/ 4 ) * sin( ( 9 pi) / 8 ) sin(pi/ 4 ) * sin( ( 9 pi) / 8 ) without using products of trigonometric functions?

1 Answer

Explanation:

Related questions

Impact of this question

How do you express $sin(pi/ 4 ) * sin( ( 9 pi) / 8 )$ without using products of trigonometric functions?