.
Since you need to verify only, I will be short.
sin(A + B) = = =
cos(A + B) = = =
tan(A + B) = .
If you want more details, see the lessons
- Calculating trigonometric functions of angles
- Advanced problems on calculating trigonometric functions of angles
in this site.
Also, you have this free of charge online textbook in ALGEBRA-II in this site
- ALGEBRA-II - YOUR ONLINE TEXTBOOK.
The referred lessons are the part of this online textbook under the topic "Trigonometry: Solved problems".
---------------
Comment from student: I did have it correct! Thank you so much!
---------------
My response: I am glad to hear it !
I am glad for myself too !!