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>
15 increased by a number x: 15 + x
a number x more than −14: x > -14
t<span>he difference of 7 and a number x: </span>7/x
Answer: I think the answer is $33.42
Explanation: If it’s $0.03 for every hour and there is only 11.14 hours used a day just multiply 11.14 by .03 and you get .3342 then you move the decimal over 2 spaces to get 33.42
Since it is a right angle you would subtract 57 from 90 because both angles added together are 90°. 90-57= 33°
Okay. For these types of problems, you must do order of operations (PEMDAS). Parenthesis, Exponents, Multiplication, Division, Addition, Subtraction. Mind you that you do these steps from left to right, and multiplication and division is done from left to right. Same thing with addition and subtraction. With that being said, here are your answers if you do the expressions correctly.
1. 12
2. 106
3. 42
