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:
y = - 4
Step-by-step explanation:
The equation of a horizontal line parallel to the x- axis is
y = c
where c is the value of the y- coordinates the line passes through
The line passes through (3, - 4 ) with y- coordinate - 4 , then
y = - 4 ← equation of line
81 degrees
1 degree = 2 pi / 360
81 degrees = 162 pi / 360
=9 pi / 20
L (arc) = radius x angle
= 10 x 9 pi / 20
90 pi /20
9/2 pi : D
The answer is D
Answer:
Step-by-step explanation:
hello :
put x = -5 in this equation : a(4-x) =-3x + b
a(4+5) =15 + b
9a = 15 +b
b = 9a - 15
the values of a and b is all order pair : ( a ; 9a-15) a real number
