Answer:
see explanation
Step-by-step explanation:
The surface area (A) of a sphere is calculated as
A = 4πr² ← r is the radius, here r = 9, thus
A = 4π × 9² = 4π × 81 = 324π ≈ 1017.9 units²
Answer:
tan(-π/3) = -1.732050808
Step-by-step explanation:
Given in the question, we have to find the value of tan(-pi/3) or it can be written as:

where x is the exact value of the given tangent.
However, in this question, one may get confused and put the value of π = 3.14, which is wrong. The value given is in radians, which is used to measure angles, just like degrees.
To make it easier, lets convert the radians into degrees. We know that
π = 180°
-π/3 = -180/3 = -60°
Find x:
x = tan (-60°)
x = -1.732050808
-- point (1, -2)
-- point (10, 25)
Answer:

Step-by-step explanation:
A function satisfying the equation
is said to be an even function. This denomination comes from the fact that the same relation is satisfied for functions of the form
with
even. Observe that if
is twice differentiable we can derivate using the chaing rule as follows:
implies 
Applying the chain rule again we have:
implies 
So we have that function
is also an even function.