# Thread: help with further trig question

1. ## help with further trig question

Hey how would this question be solved?

sin(A + B - C) cos(A - B + C) + cos (A + B - C) sin(A - B + C)

2. ## Re: help with further trig question

Use the angle sum identity:

$\sin(\alpha + \beta) =\,\, ?$

3. ## Re: help with further trig question

sin(a + b) = sin(a)cos(b) + cos(b)sin(a)

Similarly:

sin(A + B - C)cos(A - B + C) + cos(A + B - C)sin(A - B + C) = sin[(A + B - C)+(A - B + C)]
= sin(2A)

Here's the answer, little late sorry

There are currently 1 users browsing this thread. (0 members and 1 guests)

#### Posting Permissions

• You may not post new threads
• You may not post replies
• You may not post attachments
• You may not edit your posts
•