RaWr

How is this solved using trig identities (sum/difference)?

GenaCL600 [577]

FIRST PART
We need to find sin α, cos α, and cos β, tan β
α and β is located on third quadrant, sin α, cos α, and sin β, cos β are negative

Determine ratio of ∠α
Use the help of right triangle figure to find the ratio
tan α = 5/12
side in front of the angle/ side adjacent to the angle = 5/12
Draw the figure, see image attached

Using pythagorean theorem, we find the length of the hypotenuse is 13
sin α = side in front of the angle / hypotenuse
sin α = -12/13

cos α = side adjacent to the angle / hypotenuse
cos α = -5/13

Determine ratio of ∠β
sin β = -1/2
sin β = sin 210° (third quadrant)
β = 210°

$cos \beta = -\frac{1}{2} \sqrt{3}$

$tan \beta= \frac{1}{3} \sqrt{3}$

SECOND PART
Solve the questions
Find sin (α + β)
sin (α + β) = sin α cos β + cos α sin β
$sin( \alpha + \beta )=(- \frac{12}{13} )( -\frac{1}{2} \sqrt{3})+( -\frac{5}{13} )( -\frac{1}{2} )$
$sin( \alpha + \beta )=(\frac{12}{26}\sqrt{3})+( \frac{5}{26} )$
$sin( \alpha + \beta )=(\frac{5+12\sqrt{3}}{26})$

Find cos (α - β)
cos (α - β) = cos α cos β + sin α sin β
$cos( \alpha + \beta )=(- \frac{5}{13} )( -\frac{1}{2} \sqrt{3})+( -\frac{12}{13} )( -\frac{1}{2} )$
$cos( \alpha + \beta )=(\frac{5}{26} \sqrt{3})+( \frac{12}{26} )$
$cos( \alpha + \beta )=(\frac{5\sqrt{3}+12}{26} )$

Find tan (α - β)
$tan( \alpha - \beta )= \frac{ tan \alpha-tan \beta }{1+tan \alpha tan \beta }$
$tan( \alpha - \beta )= \frac{ \frac{5}{12} - \frac{1}{2} \sqrt{3} }{1+(\frac{5}{12}) ( \frac{1}{2} \sqrt{3})}$

Simplify the denominator
$tan( \alpha - \beta )= \frac{ \frac{5}{12} - \frac{1}{2} \sqrt{3} }{1+(\frac{5\sqrt{3}}{24})}$
$tan( \alpha - \beta )= \frac{ \frac{5}{12} - \frac{1}{2} \sqrt{3} }{ \frac{24+5\sqrt{3}}{24} }$

Simplify the numerator
$tan( \alpha - \beta )= \frac{ \frac{5}{12} - \frac{6}{12} \sqrt{3} }{ \frac{24+5\sqrt{3}}{24} }$
$tan( \alpha - \beta )= \frac{ \frac{5-6\sqrt{3}}{12} }{ \frac{24+5\sqrt{3}}{24} }$

Simplify the fraction
$tan( \alpha - \beta )= (\frac{5-6\sqrt{3}}{12} })({ \frac{24}{24+5\sqrt{3}})$
$tan( \alpha - \beta )= \frac{10-12\sqrt{3} }{ 24+5\sqrt{3}}$

7 0

3 years ago

What is the factored form of 3x^2 + 23x - 36?

alex41 [277]

The factored form is (3x-4)(x+9)

6 0

3 years ago

Help me solve this please. I don't know the formula for this.

den301095 [7]

Answer

48,000

Step-by-step explanation:

base(x)

1,200(40)

8 0

3 years ago

One gallon of gasoline in buffalo, New York costs $2.29. In Toronto, Canada, one liter of gas costs $0.91. There are 3.8 liters

Solnce55 [7]

<u>Answer:</u>

The cost of one gallon of gas in Toronto, Canada is $3.458.

<u>Solution: </u>

Given, One gallon of gasoline in buffalo, New York costs $2.29.

In Toronto, Canada, one liter of gas costs $0.91.

There are 3.8 liters in one gallon.

We have to find how much does one gallon of gas cost in Toronto?

Now, cost of one gallon of gas in Toronto = cost of one litre of gas in Toronto x 3.8 liters for 1 gallon.

Cost of one gallon of gas = 0.91 x 3.8 = 3.458

Hence, the cost of one gallon of gas in Toronto, Canada is $3.458.

3 0

3 years ago

If the area of the rectangle is 130 square inches then what is the rectangles height, h

fomenos

Answer:

130/l in where l is the length of the rectangle

Step-by-step explanation:

The formula for area of a rectangle is length by width where the width is the height of the rectangle

Given that area=130 in²

Lets assume the length of this rectangle is =l inches

Then ;

A=l*w

130 =l*w

130/l = w

130/l in = height

5 0

3 years ago