Sin 2 x + sin x = 0
( sin 2 x = 2 sin x cos x )
2 sin x cos x + sin x = 0
sin x ( 2 cos x + 1 ) = 0
sin x = 0
x 1 = 0
x 2 = π
or: 2 cos x + 1 = 0
2 cos x = - 1
cos x = -1/2
x 3 = 2π/3
x 4 = 4π/3
Answer:
18ft
Step-by-step explanation:
L = length
W = width
l = w + 2ft ; because the is 2 ft longer than width
The area of a rectangle is lw
You can take the first equation ( l = w + 2 ) and plug it in lw
like this: lw ---> (w+2)w = w^2+2w
then from the question you get: w^2+2w=19.25
you use the quadratic formula and get w = 3.5
then from the first equation, you get l = 3.5+ 2 so the length is 5.5
lastly, you use the perimeter formula: 2(l+w) so 2(9) = 18
so 18ft
Answer:
the answer is this graph thingy
