Show:
Half Angle
Double Angle
Sum
Difference
Name That Identity
100
Using the half angle formula, find the exact value of cos 15º.
+(√(2+√3)/2
100
simplify sec x sin 2x
2sinx
100
show that cos(pi/2 + x)=-sinx
cos(x+y)=cosxcosy-sinxsiny cos(pi/2 + x)=cos(pi/2)cosx-sin(pi/2)sinx cos(pi/2 + x)=(0)(cosx-1)-(1)(sinx) cos(pi/2 + x)=-sinx
100
find the exact value of sin(-pi/12)
(1-√3)/(2√2)
100
Which identity is Sin2x=2sinxcosx?
Double Angle Idenity
200
Find the exact value for sin 105° using the half‐angle identity.
+(√(2+√3)/2
200
find cos2x given that cosx=12/13
sinx/1+cosx
200
find the exact value of cos(5pi/12)
(√6-√2)/4
200
find the exact value of sin15º using the difference identity
(√6+√2)/4
200
Which identity is tan(x/2)=sinx/1+cosx?
half angle identity
300
Find the exact value for cos 165° using the half‐angle identity.
-(√(2+√3)/2
300
What are all the solutions for sinxcosx=1/2?
x=pi/4+pi(k)
300
simplify the expression cos(x+pi)
-cosx
300
find the exact value of tan(7pi/12)
-2-√3
300
Which identity is sin(x+y)=sinxcosy+cosxsiny?
sum and difference identity
400
Use the half angle identity to find the exact value of cos(5pi/8)
-(√(2+√2)/2
400
Use the double‐angle identity to find the exact value for cos 2 x given that sin x =√5/5.
±3/5
400
solve sin(x + pi/3)+sin(x - pi/3)=1 for 0≦x<2pi
sinx=1 x=pi/2
400
find the exact value of cos(pi/12)
(√2+√6)/4
400
which identity is tan2x=(2tanx)/(1-tan^2x)?
Double Angle identity
500
find the exact value of cos(pi/12)
+(√(2-√3)/2
500
if pi
sin2x=0.8304 cos2x=-0.5571
500
find the exact value of sin195
500
find the exact value of sin(-pi/12)
(1-√3)/(2√2)
500
Which identity is tan(x+y)=(tanx+tany)/(1-tanxtany)?
sum and difference identity