x1-cosxsinx-xcosxdx
We can start by simplifying the expression in the numerator:
x(1-cosx) = x - xcosx
Now we can rewrite the denominator using the identity sinx-xcosx=-xcosx/sinx:
sinx-xcosx = sinx - (sinx-xcosx) = 2xcosx - sinx
Substituting these expressions into the original integral, we get:
∫(x-xcosx)/(2xcosx-sinx) dx
Now we can use a substitution u = 2xcosx - sinx, which gives us du/dx = -2xsinx - cosx. Rearranging this expression, we get:
xsinx = (2xcosx - u)/2
Substituting these expressions into the integral, we get:
∫[(2xcosx-u)/2-u/2] / u du/dx dx
Simplifying the numerator, we get:
∫(3u/4 - 2xcosx) / u (-2xsinx - cosx) dx
Now we can cancel out the x terms and simplify the expression further:
∫(3/4 - u/2cosx) / u (-2sinx - 1/2cosx) dx
Using partial fractions, we can write:
(3/4 - u/2cosx) / u (-2sinx - 1/2cosx) = A/u + B/(-2sinx - 1/2cosx)
Multiplying both sides by the denominator, we get:
3/4 - u/2cosx = A(-2sinx - 1/2cosx) + B(u)
Substituting x = π/2, we get:
3/4 - 0 = B(2)
B = 3/8
Substituting x = 0, we get:
3/4 - u/2 = A(-1/2)
A = -3/4u
Substituting these values back into the partial fractions expression, we get:
(-3/4u/u) + (3/8)/(2sinx + 1/2cosx)
Simplifying, we get:
-3/4∫(1/u) du + 3/4∫(1/(2sinx + 1/2cosx)) dx
The first integral is ln|u|, and the second integral can be evaluated using a substitution v = 2sinx + 1/2cosx, which gives us:
∫(1/v) dv = ln|v| = ln|2sinx + 1/2cosx|
Substituting u = 2xcosx - sinx and simplifying, we get:
∫(x - ln|2xcosx - sinx|)/2 dx
This is the final answer.
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