is in quadrant I, so
.
is in quadrant II, so
.
Recall that for any angle
,

Then with the conditions determined above, we get

and

Now recall the compound angle formulas:




as well as the definition of tangent:

Then
1. 
2. 
3. 
4. 
5. 
6. 
7. A bit more work required here. Recall the half-angle identities:



Because
is in quadrant II, we know that
is in quadrant I. Specifically, we know
, so
. In this quadrant, we have
, so

8. 
Answer: 31500 to 38500
Step-by-step explanation:
Lets find lower limit of guess
35000 - ( 35000 * 10% )
= 31500
Upper limit of guess
35000 + ( 35000 * 10% )
= 38500
So your guess can be anything between these two values.
36 cm^2
Step-by-step explanation:
<u>Small</u><u> </u><u>window</u>
Length: 2cm
Width: 2cm
<u>Area</u><u>:</u> 4 cm^2
<u>Big window</u>
Length: 4cm
Width: 3cm
<u>Area</u><u>:</u> 12 cm^2
Total area of the windows:
(Area of 4 small windows + area of 1 big window)
(4 cm^2 x 4 + 12cm^2)
= <u>28 cm^2</u>
<u>Above</u><u> </u><u>window</u><u> </u><u>(</u><u>approx</u><u>.</u><u>)</u>
<u>Rectangle</u>
Length: 3cm
Width: 2cm
<u>Area</u><u>:</u> 6 cm^2
<u>T</u><u>riangle</u>
Base: 1cm
Height: 1cm
<u>Area</u><u>:</u> 2 x 0.5 cm^2 = 1 cm^2
<u>Square</u><u> </u><u>(</u><u>between</u><u> </u><u>the</u><u> </u><u>triangles</u><u>)</u>
Length: 1cm
Width: 1cm
<u>Area</u><u>:</u> 1 cm^2
= 8 cm^2
<u>TOTAL</u><u> </u><u>AREA</u><u> </u><u>OF</u><u> </u><u>ALL</u><u> </u><u>WINDOWS</u>
= AREA OF 4 WINDOWS + AREA OF BIG WINDOW + AREA OF ABOVE WINDOW
= 16 cm^2 + 12 cm^2 + 8 cm^2
<h3>
= <u>
36 cm^2</u></h3>
<em>I</em><em> </em><em>hope</em><em> </em><em>I</em><em> </em><em>made</em><em> </em><em>the</em><em> </em><em>explanations</em><em> </em><em>clear</em><em> </em><em>enough</em><em> </em><em>to</em><em> </em><em>make</em><em> </em><em>it</em><em> </em><em>easier</em><em> </em><em>for</em><em> </em><em>you</em><em> </em><em>to</em><em> </em><em>understand</em><em>!</em>