We expand first (cos x +cos y)^2+(sin x-sin y)^2:
= cos^2 x + 2 cos x cos y + cos^2 y+ sin ^2 x + sin ^2 y - 2 sin x sin y
= (cos^2 x + sin ^2 x) + (cos^2 y + sin ^2 y) + 2 (cos x cos y - sin x sin y)
then, apply the trigonometric identities of addition and summation of angles
= 1 + 1 + 2 cos (x+y)
we add the following identities above that results to
2 + 2 cos (x+y)
Answer:
c/16
Step-by-step explanation:
now, we know the tangent line at (2,4) is y = 8x - 12, now, that's already in slope-intercept form, so, the slope of that tangent at (2,4) is "8" then.
now, that means when x = 2, the slope is 8, so let's use that.
Answer:
B) 10x + 8y ≥ 210
Step-by-step explanation:
We know that we have to sit at least 210 people which means that we can fit more than 210, but no less than 210. This gives us a first step in solving since we know that the equation must be greater than or equal ( ≥) 210
This rules out C & D immediately.
Now we know that circular tables can sit 10 people and are represented by the variable x which means that each circular table will be equal to 10x and that rectangular tables are denoted by y and can sit 8 people making it recognizable by 8y. We know that the people sitting at all of the tables will be added up to give us a number of either 210 or more.
The only answer that gives us the tables and how many people they seat accurately is B since it is 10x and 8y. We also see that these two numbers are added together to make it greater than or equal to 210.