menty
Member
- Joined
- Feb 11, 2004
- Messages
- 119
- Gender
- Male
- HSC
- 2010
OK
when i do these questions, i usually end up in the form cosAcosB -sinAsnB = R
thats easy, its just cos (A-B) = R
if i have problems, and i wasnt b int he beginning, i just make it cos (B-A) = R (cuz cos (-A) = cos(A)
Now, what happens if i want cosAcosB + sinAsnB instead?
DOES (sinAsinB - cosAcosB) = - (cosAcosB -sinAsinB)
when i do these questions, i usually end up in the form cosAcosB -sinAsnB = R
thats easy, its just cos (A-B) = R
if i have problems, and i wasnt b int he beginning, i just make it cos (B-A) = R (cuz cos (-A) = cos(A)
Now, what happens if i want cosAcosB + sinAsnB instead?
DOES (sinAsinB - cosAcosB) = - (cosAcosB -sinAsinB)