So lets get to the problem
<span>165°= 135° +30° </span>
<span>To make it easier I'm going to write the same thing like this </span>
<span>165°= 90° + 45°+30° </span>
<span>Sin165° </span>
<span>= Sin ( 90° + 45°+30° ) </span>
<span>= Cos( 45°+30° )..... (∵ Sin(90 + θ)=cosθ </span>
<span>= Cos45°Cos30° - Sin45°Sin30° </span>
<span>Cos165° </span>
<span>= Cos ( 90° + 45°+30° ) </span>
<span>= -Sin( 45°+30° )..... (∵Cos(90 + θ)=-Sinθ </span>
<span>= Sin45°Cos30° + Cos45°Sin30° </span>
<span>Tan165° </span>
<span>= Tan ( 90° + 45°+30° ) </span>
<span>= -Cot( 45°+30° )..... (∵Cot(90 + θ)=-Tanθ </span>
<span>= -1/tan(45°+30°) </span>
<span>= -[1-tan45°.Tan30°]/[tan45°+Tan30°] </span>
<span>Substitute the above values with the following... These should be memorized </span>
<span>Sin 30° = 1/2 </span>
<span>Cos 30° =[Sqrt(3)]/2 </span>
<span>Tan 30° = 1/[Sqrt(3)] </span>
<span>Sin45°=Cos45°=1/[Sqrt(2)] </span>
<span>Tan 45° = 1</span>
Answer:
- 
i
Step-by-step explanation:
Given
Multiply numerator/ denominator by i
= 
[ i² = - 1 ]
= 
= - i
Answer:
(i) The name of the part of the circle, OQ is a radius
(ii) The radius of the sector QOR is 21 cm
Step-by-step explanation:
The given figure is a sector of the circle O
∵ Any sector of a circle formed from 2 radii and an arc
∴ OQ is a radius
(i) The name of the part of the circle, OQ is a radius
The rule of the length of an arc of a circle is L = 
× 2 π r, where
- α is the angle of the sector
- r is the radius of the circle
∵ The length of the arc QR is 22 cm
∴ L = 22
∵ The measure of the angle of the arc is 60°
∴ α = 60°
∵ π = 
→ Substitute them in the rule above
∵ 22 = 
× 2 × × r
∴ 22 = 
r
→ Divide both sides by
∴ 21 = r
(ii) The radius of the sector QOR is 21 cm
Using the least common factor, it is found that:
- a) 60 packages should be bought.
- b) There will be 5 filled goody bags.
<h3>
Least Common Factor:</h3>
- The sizes of the packages are: 10, 6, 15 and 12.
- To fill each bag and have no left-overs, the number of packages is the <u>least common factor</u> of these amounts.
- The least common factor is found factoring the numbers into prime factors.
Item a:
10 - 6 - 15 - 12|2
5 - 3 - 15 - 6|2
5 - 3 - 15 - 3|3
5 - 1 - 5 - 1|5
1 - 1 - 1 - 1
Hence, lcf(10,6,15,2) = 2 x 2 x 3 x 5 = 60.
60 packages should be bought.
Item b:
Goody bags are in packages of 12, hence:
60/12 = 5.
There will be 5 filled goody bags.
To learn more about the least common factor, you can take a look at brainly.com/question/24873870
This one is very simple.
create a simple equation to find out
15 = 12 + x
subtract 12 from each side
x= 3
the missing number is 3
or, to be even simpler, take the total, subtract the total from the number you know and the difference is the missing number.
hope I helped
ALSO, we can check going down vertically. 3 + 10 =13. this is the total listed at the bottom.
