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>
I would assume that they want a cosine value that would give the same answer. sin(30°) is equal to 1/2
Therefore cos(×) = 1/2
x = arccos(1/2)
x=60
cos(60°)
Answer:
15 months
Step-by-step explanation:
330+120=450, and 450 divided by 30 equals 15. Therefore, Sophia has saved $30 to her savings account every month for 15 months.
Answer:
One inch would represent 100 miles
Answer:
c
Step-by-step explanation:
10x10x10x10x10x10=1000000x1.2=1200000
