Answer:
15 x 1 + 5 x 3 = 30
Step-by-step explanation:
If you turn the x into a one then it multiplies 15 by one and then it remains at 15, then you multiply 5 and 3 so that's 15 and then 15 + 15 is 30.
Answer:
To convert fraction to decimal, divide 3/10, which would give you . 3 which is already a decimal. To convert decimal to percent, multiply by 100 which would give you 30, hence 30%
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.
