, %#/ 26 3. / * ( 0 ) ##
+ 1 ( 0 * + ( 2#, ) f(x) ³ 0 ( / +* " x Î [a, b] # 2, ) * 6 * + ) x Î [a, b]
/, ) * + ( #+ $
b x
( fg )(x)dx = f (a) g (x)dx.
a a
0( (# 03# # P = {x0, x1, x2, ..., xn-1, xn} 0 [a, b] * 0 # Dk = [xk-1, xk], k = 1, 2, ..., n, (# + ' ( # !, + ' (b - a)/n. 4 & ( / *+ '* + ((# #+ * # # # ' * # # & #
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n xk |
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( fg )(x)dx = ( fg )(x)dx = ( f (x) - f (xk -1 ) + f (xk -1 ))g (x)dx = |
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(1) |
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( f (x) - f (xk -1 ))g (x)dx + f (xk -1 ) g (x)dx. |
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3 0 )# |
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Sn1 = ( f (x) - f (xk -1 ))g (x)dx, Sn2 = f (xk -1 ) g (x)dx. |
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% # Sn1 |
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Sn1 |
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( f (x) - f (xk -1 ))g (x)dx |
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( f (x) - f (xk -1 ))g (x)dx |
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f (x) - f (xk -1 ) |
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g (x) |
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dx £ C |
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f (x) - f (xk -1 ) |
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dx = |
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k =1 x |
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k =1 x |
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256