1
NAME:
QUIZ 4 Precal
1 Find an expression for si n 130  in terms of 190  and 230 
using the diagram below and the Equal Chords Theorem.
2 If si n 130  = si n 10  cos 40  + si n 40  cos10 ,
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(a)
does si n 130  = cos 80  si n 50  + si n 40  cos10  ?
(b)
does si n 130  = cos 40 ?
(a) sin(A + B) =
(b) cos(A + B)=
2
4
(a) tan(A + B) =
(b) TRUE OR FALSE. cot(A + B) =
5 Simplify si n
cot A⋅cot B − 1
cot A + cot B
π
=
12
3 , in Q1 and sin β = 5 , in Q2,
β
α
5
13
then find sin α + β .
6 If sinα =
(
)
7
(a) Simplify si n
(b) Simplify
π
5π
π
5π
⋅ cos
+ c os
⋅ sin
.
18
18
18
18
tan 40 − tan10 .
1+ tan 40 ⋅ tan10