R2(<span>cos2</span>ϕ−<span>sin2</span>ϕ)−2rcosϕ=0<span><span>r2</span>(<span>cos2</span>ϕ−<span>sin2</span>ϕ)−2rcosϕ=0</span>
<span><span><span>r2</span>cos<span>(2ϕ)</span>−2rcosϕ=0</span><span><span>r2</span>cos<span>(2ϕ)</span>−2rcosϕ=<span>0
Now </span></span></span> divide through by <span><span>r≠0</span><span>r≠0</span></span>
and get
<span><span>rcos<span>2ϕ</span>−2cosϕ=0</span><span>rcos<span>2ϕ</span>−2cosϕ=0</span></span>
or
<span><span>r=2<span><span>cosϕ</span><span>cos<span>2ϕ</span></span></span></span><span>r=2<span><span>cosϕ</span><span>cos<span>2<span>ϕ</span></span></span></span></span></span>
The minimum thickness of the book would simply be the sum
of the thickness of the two cover pages and all the pages in between. That is:
minimum thickness = 0.9 mm * 2 + 0.13 mm * 400
<span>minimum thickness = 53.8 mm</span>
1/4 mile per minute is the average speed.
The Correct Answer is B
B.False
Answer:
2 ( 24 ) + 2 a = 215
Step-by-step explanation:
Perimeter of the rectangle is 215 feet, the short sides are 24 feet long and we need to work out the long sides (we will call a long side 'a') so,
24 + 24 + a + a = 215