Answer:
see explanation
Step-by-step explanation:
Using the double angle identity for sine
sin2x = 2sinxcosx
Consider left side
cos20°cos40°cos80°
=
(2sin20°cos20°)cos40°cos80°
=
(2sin40°cos40°)cos80°
=
(sin80°cos80° )
=
(2sin80°cos80° )
=
. sin160°
=
. sin(180 - 20)°
=
. sin20°
=
= right side , thus proven
Fraction is 2.161616/1000000
mixed number is 2 161616/1000000
Answer: 461.60 is the volume of liquid the tank can hold.
Step-by-step explanation:
We were given;
Height H = 9 ft
Diameter D = 14 ft
Pie π = 3.14
We will make use the formula of volume of a cone to get volume of water the tank can hold because it is said that the tank is in the shape of a cone
So
V = 1/3 * πr2h
First we need to find our radius r
Radius = 1/2 of diameter = 14/2 = 7
So using the formula
V = 1/3 * πr2h
V = 1/3 (3.14 * 7² * 9)
V = (3.14 * 49 * 9)/3
V = 1384.74 / 3
V = 461.58 = 461.60 (nearest ten)