16/21 is the correct answer
Answer:
Step-by-step explanation:
If (x+8) is a factor of f(x), then for some expression p, we have ...
f(x) = (x+8)p
Evaluated at x=-8, this gives ...
f(-8) = (-8+8)p = 0p
f(-8) = 0 . . . . must be true
_____
Similarly, f(8) = (8+8)p = 16p. This may or may not be zero, depending on the factors of p. The only offered statement that <em>must</em> be true is the one shown above.
Answer:
Step-by-step explanation:
Move 
to the denominator in 
using the negative exponent rule 
160 cm because if I am correct, then two of the sides are labeled as 10 cm. Which means that they are both the same measurement.
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.
