Answer:

Step-by-step explanation:
Given

Required
Find V when

Substitute
for r in 

Open bracket


Simplify the fractions

Let

So:




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
Answer:
52
Step-by-step explanation:
for every 4 pencils there is 1 eraser. 4/1=208/x
4x=208
x=52
Answer:
$3.51
Step-by-step explanation:
We change 5.4% into a decimal which is .054, we then multiply 65 by .054
$65 x .054 = $3.51
Answer:
It would be 125m^2
Step-by-step explanation:
17*10=170
170/2=85
8*10=80
80/2=40
85+40=125