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:
distance = 1.5 miles(approx.)
Step-by-step explanation:
given,
speed of sound = 1130 ft/s
1 ft = 0.3048
1130 ft/s = 0.3048 × 1130 m/s
= 344.424 m/s
time = 7 second
distance = speed × time
distance = 344.424 × 7
distance = 2410.968 m
1 m = 0.0006214 miles
2410.968 m = (0.0006214 × 2410.968) miles
distance = 1.498 miles
distance = 1.5 miles(approx.)
Answer:
1. if you are solving using the quadratic formula. the answer is in the first picture.
2. if you are looking to completing the square the answer is in the second picture.
Step-by-step explanation:
Answer:
2/3
Step-by-step explanation:
If we have 'x' students who like math and 'y' students that like science, we can formulate that:
Half of x likes math and science, and also one third of y likes math and science, so:
(1/2) * x = (1/3) * y
x / y = (1/3) / (1/2)
x / y = (1/3) * 2 = 2/3
So the ratio of the number of students who like math to the number of students who like science is 2/3
