Trig. Identities
Simplifying Trig. Expressions
Brain Break
Solving Trig. Equations
Do you know Ms. Mira
100

If cos x = (2/3) find sec x

What is sec x = (1/cos x)

=(1/(2/3))

=(3/2)

100

(sec2x-1)cos2x

What is (sec2x-1)cos2x

=(tan2x)cos2x    Pythagorean Identity

=((sin2x)/(cos2x))cos2x  Quotient Identity

=sin2x   Multiply and divide out common factor

100

If you bang your head against a wall for one hour you will burn this many calories.

What are 150 calories?

100

5sinx+2=sinx

What is 5 sinx+2=sinx

=4sinx+2=0

=2(2sinx+1)=0

=2sinx=-1

= sinx=(1/2)  The period of sine is (2pi), so you only need to find solutions on the interval [0,(2pi)].  The solutions on this interval are ((7pi)/6) and ((11pi)/6). Solutions on the interval(-infinity, infinity), are found by adding integer multiples of (2pi).  The general form of the solutions is: ((7pi)/6)+2npi, ((11pi)/6) + 2npi, n e Z

100

Where did Ms. Mira go to high school?

Warren & Downey High School

200

If tan a = (1/5) find cot a

What is cot a = (1/tan a )

=(1/(1/5))

=(5/1)

=5

200

sec2x(1-cos2x)

What is sec2x(1-cos2x)

=sec2x-sec2xcos2x   Distributive Property

=sec2x-(1/(cos2x))*cos2x Reciprocal Identity

=sec2x-1 Multiply and divide out common factor

=tan2x Pythagorean Identity

200

This letter was the last letter to be added to the English alphabet

J

200

2-10secx=4-9secx

What is 2-10secx=4-9secx

=-10secx=2-9secx

=-secx=2

=secx=-2  = cosx=-(1/2)

((2pi)/3)+2npi, ((4pi)/3)+2npi, neZ

200

Ms Mira played these sports in high school

Soccer and Track

300

if cos x = (1/6) and sin x = ((√35)/6) find cot x

What is cot x = ((cos x)/(sin x))

=((1/6)/(√35)/6)

=(1/(√35)) * ((√35)/(√35))

=((√35)/35)

300

sinx-sinx cos2x

What is sinx-sinx cos2x

=sinx(1-cos2x)  Factor

=sinxsin2x  Pythagorean Identity

=sin3x Multiply

300

This aquatic mammal sleeps with one eye open

What is a dolphin? Snapple Fact #760

300

5=sec2x+3

What is 5=sec2x+3

= 2=sec2x

=(+/-)(√2)=(√sec2x)

= secx=(+/-)(√2)

= cosx=(+/-)(1/(√2))*((√2)/(√2))

= cosx=(+/-)((√2)/2)

=(pi/4)+(pi/2)n, n e z

300

Ms. Mira has gone to this many LA Chargers games...

6

400

csc x - cos x cot x

What is csc x-cosx cot x = (1/sinx)-cosx(cosx/sinx)

=(1/sin x)-((cos2x)/(sinx))

=((1-cos2x)/(sinx))

=((sin2x)/(sinx))

=sinx

400

cot2x csc2x-cot2x

What is cot2xcsc2x-cot2x

=cot2(csc2x-1)  Factor

=cot2xcot2x  Pythagorean Identity

=cot4x Multiply and add exponents 

400

This is Barbie's full name

What is Barbara Millicent Roberts?  Snapple Fact #902

400

3cscx=2cscx+(√2)

What is 3cscx=2cscx+(√2)

= cscx=(√2)

= sinx=(1/(√2))*((√2)/(√2))

= sinx=(√2)/2)

=(pi/4)+2npi, ((3pi)/4)+2npi, neZ

400

What is Ms. Mira's go-to Starbucks drink?

Peach Green Tea Lemonade, Dragon Drink, or Iced Cinnamon Dolce Latte

500

csc x sec x - tan x

What is csc x sec x - tan x = (1/sinx)*(1/sinx)-(sinx/cosx)

=(1/(sinxcosx))-(sinx/cosx)

=(1/(sinxcosx))-(sinx/sinx)(sinx/cosx)

=((1-sin2x)/(sinxcosx)

=((cos2x)/(sinxcosx)

=(cosx/sinx)

=cotx

500

tanx csc2x-tanx

What is tanx csc2x-tanx

=tanx(csc2x-1) Factor

=tanx cot2x Pythagorean Identity

=((sinx)/(cosx))*((cos2x)/(sin2x)) Quotient Identities

=(cosx)/(sinx)  Multiply and divide common

=cot x quotient identity

500

Heart attacks are most prevalent on this day of the week

What is Mondays?

500

11=3csc2x+7

What is 11=3csc2x+7

= 4=3csc2x

=(4/3) = csc2x

= (+/-)((√(4/3))=(√csc2x)

=cscx = (+/-)(2/(√3))or(+/-)(2(√3)/3)

= sinx=(+/-)(√3/2)

= (pi/3)+2npi, (2pi/3)+2npi, (4pi/3)+2npi, (5pi/3)+2npi, nez

500

When is Ms. Mira's birthday?

January 14th