Answer:
Step-by-step explanation:
![S_{31} = 9 \cdot 31 + [-0.5 \cdot \frac{31(31-1)}{2}] = 46.5](https://tex.z-dn.net/?f=S_%7B31%7D%20%3D%209%20%5Ccdot%2031%20%2B%20%5B-0.5%20%5Ccdot%20%5Cfrac%7B31%2831-1%29%7D%7B2%7D%5D%20%3D%2046.5)
![S_{40} = 40 + [-3 \cdot \frac{40(40-1)}{2}] = -2300](https://tex.z-dn.net/?f=S_%7B40%7D%20%3D%2040%20%2B%20%5B-3%20%5Ccdot%20%5Cfrac%7B40%2840-1%29%7D%7B2%7D%5D%20%3D%20-2300)
Answer:
B
Step-by-step explanation:
-11-34 the answer will be -45 so option B is the best posible answer.
Remember that transformation between Cartesian and polar system are:
x=r*cos(α)
y=r*sin(α)
From this we can conclude that:
r=√(x^2 + y^2)
Using trigonometry transformations we can write:
r=sin(2α) = 2sin(α)cos(α)
Now we can multiply both sides with r^2:
r^3 = 2(r*sin(α))*(r*cos(α))
Now using some replacements we can write:
(x^2 + y^2)^(3/2) = 2*x*y
Answer:
933.3333333
Step-by-step explanation:
