Precalc Accel
Trig Identities/Proof – 2007
Assign #8
Name: _____________________________
Today’s preparation determines
tomorrow’s achievements
Directions: Prove each of the following.
1. sin x cot x + cos x tan x = 1
2
3.
2
2
2
sin 2x cos 2x
!
= sec x
sin x
cos x
5. Determine the symmetry (even/odd/neither) of
a. f( x ) = cos( 5x ) + 2
Answers:
5. a. even b. odd
2. sin( x + y )sin( x ! y ) = sin2 x ! sin2 y
4.
"
! % 1 + tan x
tan $ x + ' =
4 & 1 ( tan x
#
b. f( x ) = cot( 3x )