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:420
Step-by-step explanation:
Answer:
(-3,4), (-3,1), and (-5,1)
2001: 11
2002: 15
2003: 19
2004: 17
2005: 23
2006: 20
2007: 17
2008: 13
2009: 18
2010: 21
Add all the numbers (174) not including the years and then divide by how many years there are (10) 17.4
The answer is A
Answer:
A
Step-by-step explanation:
Given
= 13x
Multiply both sides by 2 to clear the fraction on the left side
x + 50 = 26x ( subtract x from both sides )
50 = 25x ( divide both sides by 25 )
2 = x ⇒ x = 2 → A
