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>
Answer:
3
Step-by-step explanation:
(x₁ , y₁) = (-1 , -2) & (x₂ , y₂) = (3 , 10)
![= \frac{10-[-2]}{3-[-1]}\\\\=\frac{10+2}{3+1}\\\\=\frac{12}{4}\\\\=4](https://tex.z-dn.net/?f=%3D%20%5Cfrac%7B10-%5B-2%5D%7D%7B3-%5B-1%5D%7D%5C%5C%5C%5C%3D%5Cfrac%7B10%2B2%7D%7B3%2B1%7D%5C%5C%5C%5C%3D%5Cfrac%7B12%7D%7B4%7D%5C%5C%5C%5C%3D4)
m = 4
y - y₁ = m (x - x₁)
y - [-2] = 4(x - [-1])
y + 2 = 4(x + 1)
y + 2 = 4x + 4
y = 4x + 4 - 2
y = 4x + 2
Ok so..... u go on the y axis and u go to 3 over 4 put a dot there and go to -8 put a dot there and then u connect them sorry
