The correct answer is the first option, which is:
(–7 + i) + 7i = –7 + (i + 7i)
The explanation is shown below:
1. By definition, in the associate property of addition you summ the number by grouping them with parenthesis, without matter where you use those parenthesis.
2. Therefore, as you can see, you can obtain the result of the addition by agruping the numbers <span>(–7 + i) + 7i or –7 + (i + 7i)</span> .
Sin(13π/8) , is in quadrant IV so the angle will be negative, find the reference angle.
<span>sin(13π/8) = -sin(16π/8 - 13π/8) = -sin(3π/8) = -cos(4π/8 - 3π/8) = - cos(π/8). </span>
<span>Use half angle formula for cos(x): </span>
<span>cos²(x/2) = (cos(x) + 1) / 2 </span>
<span>Let x = π/4 </span>
<span>cos²(π/8) = (cos(π/4) + 1) / 2 </span>
<span>cos²(π/8) = (√(2) / 2 + 1) / 2 </span>
<span>cos(π/8) = √(√(2) / 4 + 1/2) </span>
<span>-cos(π/8) = -√((√(2) + 2) / 4)</span>
<span>Which expression can be used to determine the side length of the rhombus?
The answer is the first option: 10/Cos(30°) Explanation:
1. As you can see in the figure attached, there is a right triangle and its hypotenuse (which is represented with the letter "x") is the side you want to calculate. So, you have:
Cos(</span>α)=Adjacent leg/Hypotenuse
<span>
</span>α=30°
<span> Adjacent leg=(20 in)/2=10 in
Hypotenuse=x
2. When you substitute these values into the formula, you obtain:
</span>
Cos(α)=Adjacent leg/Hypotenuse
<span> Cos(30°)=10/x
3. Therefore, you obtain the expression to determine the side length of the rhombus by clearing the hypotenuse "x", as below:
x=10/Cos(30°)
</span>
The answer would be A because (2,100) crosses the lines on the graph.