Recall the half-angle identity:
cos²(x) = 1/2 (1 + cos(2x))
Let x = 75°, so that 2x = 150°. Then
cos²(75°) = 1/2 (1 + cos(150°))
You might already be aware that cos(150°) = -√3/2, so
cos²(75°) = 1/2 (1 - √3/2)
cos²(75°) = 1/2 - √3/4
cos²(75°) = (2 - √3)/4
But this is the square of the number we want, which we solve for by taking the square root of both sides. This introduces a second solution, however:
cos(75°) = ± √[(2 - √3)/4]
cos(75°) = ± √(2 - √3)/2
75° falls between 0° and 90°, and you should know that cos(x) is positive for x between these angles. This means cos(75°) must be positive, so we pick the positive root:
cos(75°) = √(2 - √3)/2
Answer:
$6.615
Step-by-step explanation:
Okay, does the value 3.5 represent the quantity of rice bought?
Let us assume this answer is yes, then we can go ahead and estimate the cost of the rice as
Total Cost =1.89*3.5
Total Cost =$6.615
Answer:
38 million
Step-by-step explanation:
Answer:
Im sorry but I am not really sure myself ! I hope you find or found your answer already !
Step-by-step explanation:
