Answer:
The number N of bacteria in a refrigerated food is given by N(T) = 10T^2 - 20T + 600, 2 ≤ T ≤ 20 where T is the temperature of the food in degrees Celsius. When the food is removed from refrigeration, the temperature of the food is given by T(t) = 3t + 2, 0 ≤ t ≤ 6 where t is the time in hours.
Step-by-step explanation:
The answer is (-2, -6)
to rotate 90 degrees counterclockwise, you do (-y, x)
Answer:
B.
Step-by-step explanation:
You can't have the same X values for two different Y values
in this case 19 goes with 11 and 10 in the pairs (19,11) and (19,10)
Answer and Step-by-step explanation: Spherical coordinate describes a location of a point in space: one distance (ρ) and two angles (Ф,θ).To transform cartesian coordinates into spherical coordinates:


For angle θ:
- If x > 0 and y > 0:
;
- If x < 0:
; - If x > 0 and y < 0:
;
Calculating:
a) (4,2,-4)
= 6
For θ, choose 1st option:
b) (0,8,15)
= 17


The angle θ gives a tangent that doesn't exist. Analysing table of sine, cosine and tangent: θ = 
c) (√2,1,1)
= 2

= 

d) (−2√3,−2,3)
= 5

Since x < 0, use 2nd option:



Cilindrical coordinate describes a 3 dimension space: 2 distances (r and z) and 1 angle (θ). To express cartesian coordinates into cilindrical:

Angle θ is the same as spherical coordinate;
z = z
Calculating:
a) (4,2,-4)
= 

z = -4
b) (0, 8, 15)
= 8

z = 15
c) (√2,1,1)
= 

z = 1
d) (−2√3,−2,3)
= 4

z = 3
-4x/5≥1/10
-8x≥1
x≤-1/8
x∈(-∞;-1/8]