Question

Find the exact value of the expension.
sin(7pi/24)cos (pi/8)-cos(7pi/24)sin(pi/8)
A)(squareroot2)/2
B)1
C)1/2
D)(squareroot3)/2
@ganeshie8

Answer 1

hint : sin(A-B)

Answer 2

\[\sin (A-B) = \sin A \cos B - \cos A \sin B\]

Answer 3

you need to apply it in reverse..

Answer 4

???????

Answer 5

\[\sin(7\pi/24)\cos (\pi/8)-\cos(7\pi/24)\sin(\pi/8) = \sin (7\pi/24 - \pi/8 ) \]

Answer 6

simplify

Answer 7

\[\sin(7\pi/24)\cos (\pi/8)-\cos(7\pi/24)\sin(\pi/8) = \sin (7\pi/24 - \pi/8 ) \\ = \sin (4 \pi/24) = \sin (\pi / 6) = ?\]

Answer 8

1/2

Answer 9

\(\large \color{red}{\checkmark }\)

Answer 10

is that the answer

Answer 11

ok 2 more and we are done thank you so much

Answer 12

np :)