The question is related to trigonometry and we have to use the formula of double angle .
Here we use double angle formula of tangent function which is

Given expression is

Comparing it with double angle formula, we will get x = 5
SO the required expression is equal to


So the answer is tan(10) .
(1.6x + 3.25) + (0.3x + 0.5)
combine like terms
1.6x+.3x +3.25 +.5
Result:
1.9 x + 3.75
Answer:
The volume of the observatory is 497.43 
Step-by-step explanation:
i) The diameter of the floor is 10 feet. The floor is circular and has a radius,
r =
= 5 feet.
Therefore the area of the circular floor of the observatory
=
= 3.14159 ×
= 78.54 
ii) The observatory is made up of two parts
a) 3 foot tall cylinder
∴ volume of cylinder =
× h
= 78.54 × 3
= 235.62 
b) hemisphere =
×
= 0.6667 × 78.54 × 5 = 261.81 
c) Therefore the total volume of the observatory is = a) + b)
= 235.62 + 261.81 = 497.43 
Answer: is this an acute im confused
Step-by-step explanation: