Cos(A-B) = cosAcosB + sinAsinB
<span>
cos(</span>π/2 - θ) = cos(π/2)cosθ + sin(π/2)sinθ
π/2 = 90°
cos(π/2) = cos90° = 0. sin(π/2) = sin90° = 1
cos(π/2 - θ) = cos(π/2)cosθ + sin(π/2)sin<span>θ
</span>
= 0*cosθ + 1*sin<span>θ = </span>sin<span>θ
Therefore </span>cos(π/2 - θ) = sin<span>θ
QED </span>
99-21=78
Answer:The floor lamp costs $78
Answer:
$68.48
Step-by-step explanation:
You want to find cost such that ...
6.25% × cost = $4.28
Dividing by the coefficient of cost, we get ...
cost = $4.28/0.0625 = $68.48
The answer is 1808.64 ft²
To calculate area of square we need to find radius r. Radius is a half of a diameter:
r = d/2
The blueprint:
d = 18 cm
r = 18/2 = 9 cm
<span>The blueprint has a scale of three centimeters to four feet. Actual radius r1 is:
</span>3 cm : 4 ft = 18 cm : r1
After crossing the products:
r1 = 4 ft * 18 cm : 3 cm
r1 = 24 ft
The area of the circular base of the fountain is:
A = r1² * π
π = 3.14
r1 = 24 ft
A = 24² * 3.14
A = 1808.64 ft²
Answer:
3 and 5
Step-by-step explanation:
3+5=8, and also
3x5=15
