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
The answer would be x= 4,-4
Your answer is 5.
On the first triangle ABC, the answers are all divided by 7, to the triangle DEF. So 35/7 is 5. Hope this helps.
Answer:
80 degrees
Step-by-step explanation:
the angles in a triangle all add up to 180 degrees
The larger angle is 55 deg at the larger angle.
We have to know which angles are called Complementary Angles...
if we add two angles and the total will be equal to 90 deg
let's say one angle is x and another angle is y
as they are complementary angles from the definition we can write the equation x + y = 90
one angle is 20 deg more than another one so from the above condition we write x = 20 + y
Substitute the value of x in the first eaquation we get, 20 + y + y = 90
Then, 20 + 2y = 90
subtracting 20 from both sides,
2y = 90-20 = 70
dividing both sides by 2,
2y/ 2 = 70 / 2
y = 35
So we got one angle is 35 deg
another angle is 35 + 20 = 55 deg.
Our answer is 55 deg the larger angle.
To learn more about the measure angle visit:
brainly.com/question/25716982
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