Convert the mixed number into a decimal and multiply on a calculator (or by hand).
5% of $50 = 5/100 x 50 = $2.50
Total = 50 + 2.50 = $52.50
The saes tax is $2.50; her total cost of the shirt is $52.50
3.4 - 2/3 > x
2) simplify 3.4 - 2/3 to 8.2/3
8.2/3 > x
3) Simplify 8.2/3 to 2.733333.
2.733333 > x
switch sides
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.
The original price is $1624.242424 more than likely it was $1,624.25.
