Answer:
{0, 150} degrees
Step-by-step explanation:
Given 2cos^2x-cost-1=0, let's simplify this problem by temporarily replacing cos x with y:
2y^2 - y -1 = 0
This can be solved by factoring: (2y + 1)(y - 1) = 0. From this we get two solutions: y = -1/2 and y = 1.
Remembering that we let y = cos x, we now solve:
cos x = -1/2 and cos x = 1.
Note that cos x = 1 when x = 0 and the "adjacent side" coincides with the hypotenuse.
cos x = -1/2 when the hypotenuse is 2 and the "adjacent side" is -1. This has two solutions between 0 and 360 degrees: 150 degrees and 270 degrees.
Four answer choices are given. Both (a) (0 degrees) and (b) (150 degrees) satisfy the original equation. Thus, the solution set is {0, 150} (degrees).
Answer: D
Step-by-step explanation:
because its right
Answer:
Top prism = 262 in.² Bottom prism = 478 in.²
Step-by-step explanation:
top prism:
front + back: 5 x 3 = 15
sides: 19 x 4 x 2 = 152
bottom: 19 x 5 = 95
15 + 152 + 95 = 262
bottom prism:
front + back: 5 x 6 x 2 = 60
sides: 19 x 6 x 2 = 228
top + bottom: 19 x 5 x 2 = 190
60 + 228 + 190 = 478
Answer: C=[ (10) x (19.60)÷ (8)]
Step-by-step explanation:
Given , The cost of 8 books = $ 19.60
Then, By UNITARY method , the cost of one book = ( Cost of 8 books ) ÷ ( 8)
i.e. The cost of one book = ($19.60) ÷ ( 8) ...(i)
Now , cost of 10 books = (10) x (Cost of one book)
From (i) , we get
Cost of 10 books =$[ (10) x (19.60)÷ (8)]
Let C be the cost of 10 books ( in dollars) .
So , the equation would help determine the cost of 10 :
C=[ (10) x (19.60)÷ (8)]
