Answer:
162
Step-by-step explanation:
Step-by-step explanation:
well, when 6 CD cases are 66 mm high, then 1 CD case is 66/6 = 11 mm high.
a)
therefore, 10 CD cases are 11×10 = 110 mm high.
b)
y = 11x
Answer: x= 1, 
Step-by-step explanation:
The quadratic equation is

and

So we just need to sub in the proper numbers from the equation given, in this case, it would result in

and

Once we get this we can either manually simplify or use a calculator, using a calculator would result in the answers
x= 1, 
Recall that
sin²(<em>x</em>) = (1 - cos(2<em>x</em>))/2
so that
sin²(7<em>π</em>/8) = (1 - cos(7<em>π</em>/4))/2
sin²(5<em>π</em>/8) = (1 - cos(5<em>π</em>/4))/2
Then
sin²(7<em>π</em>/8) + sin²(5<em>π</em>/8) = (1 - cos(7<em>π</em>/4) + 1 - cos(5<em>π</em>/4))/2
… = 1 - 1/2 (cos(7<em>π</em>/4) + cos(5<em>π</em>/4))
… = 1 - 1/2 (1/√2 - 1/√2)
… = 1