April 6, 2017
April 6, 2017
April 6, 2017
April 6, 2017
sec. 5.4: Sum and Difference Identities
sin(A+B) = sinAcosB + cosAsinB
sin(A-B) = sinAcosB - cosAsinB
cos(A+B) = cosAcosB - sinAsinB
cos(A-B) = cosAcosB + sinAsinB
April 6, 2017
Ex.
cos(7x)cos(5x) + sin(7x)sin(5x) =
Ex. sin(4x)cos(x) + cos(4x)sin(x) =
Ex.
=
Ex.
cos(12)cos(18) - sin(12)sin(18) =
April 6, 2017
Ex. Verify:
sin(π - A) = sin A
Ex.
Use angle sum identities to find...
sin(75)
April 6, 2017
Ex.
Use angle difference identities to find...
sin(75)
Ex.
In Q1, cosA = 3/5
In Q2, cosB = -5/13
find sin(A+B)
April 6, 2017
p. 381 # 11a – 14a, 31 – 44