Do you know the identities? (I would like to learn them)
Use the cosine , sine and tangent sum and difference identities to simplify each of the following:
1.) cos (A + B) + cos (A - B)
2.) cos (A + B) - cos (A - B)
3.) sin (A + B) + sin (A - B)
4.) sin (A + B) - sin (A - B)
5.) tan20degrees + tan32degrees / (1- tan 20degrees X tan 32 degrees)
6.) tan 35 degrees - tan 12 degrees / ( 1 + tan 35 degrees X tan 12 degrees)
here it is:
cos ( A + B ) = cos A cos B + sin A sin B
cos ( A + B ) = cos A cos B - sin A sin B
sin ( A + B ) = sin A cos B + cos A sin B
sin ( A - B) = sin A cos B - cos A sin B
tan ( A - B ) = tan A - tan B / ( 1 + tan A tan B)
tan ( A + B) = tan A + tan B / (1 - tan A tan B)
im not sure w/ my answers... but it says simplify
my answer in number 1 is 2cosAcosB am i correct?
Hello, Adam!
Do you need to see the steps?
I'll do a few of them . . .
Use the cosine, sine and tangent sum/difference identities to simplify:
We have: . .
Then: .
. . . . . . . . . . . . . . . .
We have: . .
Then: .
. . . . . . . . . . . . . . . .
We're exprected to recognize the form: .
Therefore: .