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11.2 Negative and Pythagorean Identities Write your questions here! NOTES
Identities for Negatives
Reduce to a single Trig expression
Ex 1:
Ex 2:
Pythagorean Identities
Reduce to a single Trig expression
Ex 3:
HOT TIP #1:
Write
everything in sin
and cos! Verify the following identity
HOT TIP
Ex 4:
#2: Look for
HOT TIP #3: Use
Ex 5:
algebra to make
equivalent
an identity! expressions! Verify the following identity
Ex 6:
HOT TIP #4:
Combine the
fractions. Bring the PAIN!
Bring the HEAT!
Ex 7:
Ex 8:
Now, summarize your notes here! SUMMARY:
PRACTICE
11.2 Negative and Pythagorean Identities Directions: Simplify to a single trig expression.
!"# !! !"#(!!)
1) sin βˆ’π›Ό cot(βˆ’π›Ό)
2)
3)
!"!(!!)
Directions: Verify the identity.
4) 𝑠𝑖𝑛! π‘₯ + sin π‘₯ π‘π‘œπ‘  ! π‘₯ = sin π‘₯
6)
!!!"# !
!!!"# !
= tan 𝛾
5)
7)
!
!"# ! !
!"# !
(!!!"# !)(!!!"# !)
!"# ! !
!
+ !"! ! ! = 1
!"# !
+ !!!"# ! = 2 sec π‘₯ !!!"# !
8) π‘‘π‘Žπ‘›! πœƒ π‘π‘œπ‘  ! πœƒ = 1 βˆ’ π‘π‘œπ‘  ! πœƒ 9)
10) π‘π‘œπ‘  ! Ξ» + π‘‘π‘Žπ‘›! πœ† π‘π‘œπ‘  ! πœ† = 1
!"# !
!"! !
11)
12) sin 𝛽 (csc 𝛽 βˆ’ sin 𝛽) = π‘π‘œπ‘  ! 𝛽
13)
+
!"# !!!
!"# !
!"# !
=1
!"# !!!
+ !"# !!! = 0
!"# !!!
cot π‘₯ βˆ’ tan π‘₯ =
! !"# ! !!!
!"# ! !"# !
14) 𝑠𝑖𝑛! π‘₯ π‘π‘œπ‘  ! π‘₯ = (𝑠𝑖𝑛! π‘₯ βˆ’ 𝑠𝑖𝑛! π‘₯)(cos π‘₯) 15)
π‘π‘œπ‘  ! π‘₯ =
!"! ! !"# !
!"# !!!"# !
Review Skillz: Solve each triangle. (find all sides and angles).
16)
17)
11.2 Application and Extension
1) Simplify to a single trig expression.
!"# !!!"# !
!"! !
2) Verify the identity.
π‘π‘œπ‘  ! π‘₯ + π‘π‘œπ‘  ! π‘₯ π‘‘π‘Žπ‘›! π‘₯ = 1 3) For each equation try the following values
! ! !
π‘₯ = 0, πœ‹, ! , ! , !
and calculate both the left and right sides
of the equation. If the equation is an identity, VERIFY IT! If it is not an identity, find a value of x for which
both sides are defined but not equal.
a) 𝑠𝑖𝑛! π‘₯ βˆ’ π‘π‘œπ‘  ! π‘₯ = βˆ’1
4) BRING THE PAIN!
b) π‘‘π‘Žπ‘›! π‘₯ βˆ’ 𝑠𝑖𝑛! π‘₯ = π‘‘π‘Žπ‘›! π‘₯ 𝑠𝑖𝑛! π‘₯
Use your graphing calculator and determine which of the following three equations is a
trig identity. Then verify it!
!"#! !!! !"# !!!
!"#(!!)
=1
!"# ! !"#(!!)
!"# ! !
!!!"# !
= !!!"# !
sin π‘₯ +
!"# ! !
!"# !
= sec π‘₯