I assume you're supposed to establish the identity,
cos(A) cos(2A) cos(4A) = 1/8 sin(8A) / sin(A)
Recall the double angle identity for sine:
sin(2<em>x</em>) = 2 sin(<em>x</em>) cos(<em>x</em>)
Then you have
sin(8A) = 2 sin(4A) cos(4A)
sin(8A) = 4 sin(2A) cos(2A) cos(4A)
sin(8A) = 8 sin(A) cos(A) cos(2A) cos(4A)
==> sin(8A)/(8 sin(A)) = cos(A) cos(2A) cos(4A)
as required.
Answer:
y=-1/5x-16/15
Step-by-step explanation:
slope intercept form y=mx+b
3x+15y=-16
15y=-3x-16 divide both sides by 15
y=-3/15x-16/15 simplify -3/15 to -1/5
y=-1/5x-16/15
Answer:
y = 2/5x + 3
Step-by-step explanation:
Answer:
x = (-28)/11
Step-by-step explanation:
Solve for x:
(55 x)/24 + 35/6 = 0
Put each term in (55 x)/24 + 35/6 over the common denominator 24: (55 x)/24 + 35/6 = (55 x)/24 + 140/24:
(55 x)/24 + 140/24 = 0
(55 x)/24 + 140/24 = (55 x + 140)/24:
(55 x + 140)/24 = 0
Multiply both sides of (55 x + 140)/24 = 0 by 24:
(24 (55 x + 140))/24 = 24×0
(24 (55 x + 140))/24 = 24/24×(55 x + 140) = 55 x + 140:
55 x + 140 = 24×0
0×24 = 0:
55 x + 140 = 0
Subtract 140 from both sides:
55 x + (140 - 140) = -140
140 - 140 = 0:
55 x = -140
Divide both sides of 55 x = -140 by 55:
(55 x)/55 = (-140)/55
55/55 = 1:
x = (-140)/55
The gcd of 140 and 55 is 5, so (-140)/55 = (-(5×28))/(5×11) = 5/5×(-28)/11 = (-28)/11:
Answer: x = (-28)/11
