# Trigonometric Functions and Graphs Fitzpatrick Questions (1 Viewer)

#### frankfurt

##### New Member
Hi everyone,

I had a question from Fitzpatrick 2U Chapter 12 Exercise 12.2 Question 5.d

Solve, for $\bg_white -2\pi \leq x \leq 2\pi, 2\cos2(x/3-(2\pi)/3)=\sqrt3$

#### beetree1

##### Well-Known Member
Not 100% sure if my answer is correct but:

#### mikikieko12

##### Member
An alternate method:

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#### Drongoski

##### Well-Known Member
Solution very nicely set out and handwriting really neat.

p/s: 3 values; yours correct.

Last edited:

#### mikikieko12

##### Member
Solution very nicely set out and handwriting really neat.
I checked the solutions in Pearson textbook. They are correct.

#### frankfurt

##### New Member
Thanks everyone,

Do guys know how to do these ones as well? They're from the same textbook, Fitzpatrick, Exercise 12.2 Question 7

#### CoolKids101

##### New Member
Thanks everyone,

Do guys know how to do these ones as well? They're from the same textbook, Fitzpatrick, Exercise 12.2 Question 7

View attachment 28812
For (a) and (b), you can either use t-formula or auxiliary angles, but not sure if they are in 2U. For (c), try converting sec and tan to cos and sine and then simplify, and for (d) simply use your double angle formula's and simplify

#### frankfurt

##### New Member
There were some other ones I didn't understand from this chapter either, could you please help me out with these ones too?

From Exercise 12.3:
Question 7

Question 8

From Exercise 12.4:
Question 2.e (I've attached the entire question for convenience)

Question 7.c and d (I've attached the entire question for convenience)

From the Chapter Review:
Question 1

Question 7

#### mikikieko12

##### Member
Thanks everyone,

Do guys know how to do these ones as well? They're from the same textbook, Fitzpatrick, Exercise 12.2 Question 7

View attachment 28812
Worked Solutions from Textbook:

#### frankfurt

##### New Member
For (a) and (b), you can either use t-formula or auxiliary angles, but not sure if they are in 2U. For (c), try converting sec and tan to cos and sine and then simplify, and for (d) simply use your double angle formula's and simplify
Pretty sure that T-formula and auxiliary angles are in 3u but I was wondering if there was a way to solve this question using 2u content

#### mikikieko12

##### Member
There were some other ones I didn't understand from this chapter either, could you please help me out with these ones too?

From Exercise 12.3:
Question 7
View attachment 28813

Question 8
View attachment 28814

From Exercise 12.4:
Question 2.e (I've attached the entire question for convenience)
View attachment 28815

Question 7.c and d (I've attached the entire question for convenience)
View attachment 28816

From the Chapter Review:
Question 1
View attachment 28817

Question 7
View attachment 28818

I only have worked solutions for every odd question, here are the ones from the textbook for odd questions:
12.3

12.4

Chapter Review

#### tito981

##### Member
Thanks everyone,

Do guys know how to do these ones as well? They're from the same textbook, Fitzpatrick, Exercise 12.2 Question 7

View attachment 28812
for (a), divide both sides by cosx, then square both sides, use the identity tan^2(x)+1=sec^2(x) to get the equation in terms of tan^2(x), then solve as usual. This method can be applied to all of 7. (note this may give extra solutions plug back in to verify, and also it may miss some solutions, nothing you can do).