Answer:
see explanation
Step-by-step explanation:
Using the trigonometric identity
sin²x + cos²x = 1
Consider the left side
2cos²A - 1 ← replace 1 by sin²A + cos²A
= 2cos²A - ( sin²A + cos²A)
= 2cos²A - sin²A - cos²A
= cos²A - sin²A = right side ⇒ verified
Answer:
42.5
Step-by-step explanation:
calculatour
Moving left subtracts from the x value the number you move.
In (2,9) the x value is the number 2
You move 1 unit to the left so subtract 1 from 2:
2-1 = 1
You will be at (1,9)
now, notice, the rate of change for downloading is negative, because, "y" is decreasing, namely the Mbs to be downloaded, are less and less and less as the minutes go by, because the file is almost fully downloaded
so is -4.8
now... at 8minutes, there are 9.6Mbs to download
bear in mind that 9.6 is just 4.8 * 2
that simply means, another minute, another 4.8 Mbs, and another minute and another 4.8 Mbs and the file is done
so, the file downloaded really in 10minutes
now, we know the rate is -4.8 or -24/5, let us nevermind the sign for now
since we know the file is downloading at 24Mbs in 5minutes, a rate of 24/5
how much is it for 10 minutes? well 10 is really just 5 * 2
so if it downloads at a rate of 24Mbs per 5mins, in 10 minutes it downloaded 24*2 or 48Mbs
Ugh, more algebra pretending to be geometry. Why?
This is a pretty awful instance of the genre, with no units on the constant 16, assumed to be degrees.
The total arc measure in a circle is 360 degrees. Geometry part over.
3m + 16 + 2m + 3m = 360
8m = 344
m = 344/8 = 43
Arc measures:
Arc 3m+16 = 3(43)+16 = 145°. The angle subtended by that arc is half that, 145/2=72.5°
Arc 2m=2(43)=86°. The angle subtended is half that, 43°
Arc 3m=3(43)=129°. The angle subtended is half that, 64.5°
