Recall the double angle identity,
sin(2x) = 2 sin(x) cos(x)
Then we can write
sin(9x) cos(9x) = 1/2 sin(2 • 9x) = 1/2 sin(18x)
Then
∫ sin(9x) cos(9x) dx
= 1/2 ∫ sin(18x) dx
= -1/2 • 1/18 cos(18x) + C
= -1/36 cos(18x) + C
though you could continue with another double angle identity,
cos(2x) = cos²(x) - sin²(x)
to rewrite the antiderivative as
= -1/36 (cos²(9x) - sin²(9x)) + C
= 1/36 (sin²(9x) - cos²(9x)) + C
Answer:
Taking square-root of numbers
Step-by-step explanation:
The reason is that the square-root of most numbers is an irrational number because the answer we have can not be written as p/q form. For example, if we take the example of √2 then the answer we have is "1.4142135623730950..." which can not be written in p/q form. Hence taking square-root of numbers will most likely give an irrational number.
Answer:
$ 60
Step-by-step explanation:
hope it helps!
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Is it 116? if i didnt add that up wrong thats the answer
