CALKA N I E OZN ACZON A D E FIN ICJA . N ie c h f b e d z ie fu n kc ja o kr e s lo n a w p e wn ym p r z e d z ia le I. Calk nieoznaczon a a fu n kc ji f n a z ywa m y ka zŁd a fu n kc je F r o zŁn ic z ko wa ln a w I i s p e ln ia ja c a d la ka zŁd e g o x " I wa r u n e k F2 ( x) = f( x) . P is z e m y: F( x) = f( x) dx. Mo wim y, zŁe f je s t c a lko wa ln a w I. U W A GA 1 . Gd y F( x) je s t c a lk fu n kc ji f( x) , t o F( x) + C t e zŁ je s t c a lk t e j a a fu n kc ji. W yjaśnienie: [F( x) + C]2 = F2 ( x) + C2 = F2 ( x) + 0 = F2 ( x) = f( x) . U W A GA 2 . D wie c a lki F1( x) i F2( x) t e j s a m e j fu n kc ji f( x) r o zŁn i s ie w c a lym a p r z e d z ia le I o p e wn a s t a la . W yjaśnienie: F12 ( x) = f( x) o r a z F22 ( x) = f( x) , wie c [F1( x) - F2( x) ]2 = 0 ; z wn io s ku 3 p o t wie r d z e n iu L a g r a n g e a wie m y, zŁe je d yn ie p o c h o d n a fu n kc ji s t a le j je s t s t a le r o wn a z e r o , c z yli is t n ie je t a ka s t a la C, zŁe F1( x) - F2( x) = C. W N IOS E K . Zn a ja c je d n a c a lke F fu n kc ji f o t r z ym a m y ws z ys t kie p o z o s t a le : f( x) dx = F( x) + C. TW IE R D ZE N IE . K a zŁd a fu n kc ja c i g la je s t c a lko wa ln a . a P OD S TA W OW E W ZOR Y ( c z e s c p ie r ws z a ) . Ca lko wa n ie o d n o s i s ie d o t yc h p r z e d z ia lo w, w kt o r yc h fu n kc je p o d c a lko we s a o kr e s lo n e . 1 xadx = xa+1 + C d la a = -1 ( 1 )
a + 1 1 dx = ln |x| + C ( 2 ) x exdx = ex + C ( 3 ) ax axdx = + C ( 4 ) ln a s in xdx = - c o s x + C ( 5 ) c o s xdx = s in x + C ( 6 ) 1 dx = t g x + C ( 7 ) 2 c o s x 1 dx = -c t g x + C ( 8 ) 2 s in x 1 dx = a r c t g x + C = -a r c c t g x + K ( 9 ) 1 + x2 1 1 " dx = a r c s in x + C = - a r c c o s x + K ( 1 0 ) 1 - x2 W L A S N OS CI. [f( x) ą g( x) ]dx = f( x) dx ą g( x) dx f( x) dx = f( x) dx f2 ( x) dx = f( x) + C 2 f( x) dx = f( x) CA L K OW A N IE P R ZE Z CZE S CI: u( x) v2 ( x) dx = u( x) v( x) - u2 ( x) v( x) dx Za kla d a m y t u , zŁe fu n kc je u( x) i v( x) m a j c ia g le p o c h o d n e . a W yprowadzenie wzoru: 2 ( uv) = u2 v + uv2 2 ( uv) dx = ( u2 v + uv2 ) dx uv = u2 vdx + uv2 dx uv2 dx = uv - u2 vdx P R ZY K L A D . u=x v2 =ex xexdx = = xex - 1 exdx = xex - ex + C u2 =1 v=ex CA L K OW A N IE P R ZE Z P OD S TA W IE N IE : f( x) dx = f[Ć( t) ]Ć2 ( t) dt, g d z ie x = Ć( t) Za kla d a m y t u , zŁe fu n kc ja Ć : ( ą, ) ( a,b) m a c ia g la p o c h o d n a Ć2 o r a z zŁe fu n kc ja f : ( a, b) R je s t c ia g la . W yprowadzenie wzoru: N ie c h F( x) = f( x) dx ( o z n a c z a t o , zŁe F2 ( x) = f( x) ) . Fu n kc ja z lo zŁo n a F[Ć( t) ] m a p o c h o d n a ( wz g le d e m t) 2 F[Ć( t) ] = F2 [Ć( t) ]Ć2 ( t) = f[Ć( t) ]Ć2 ( t) . Za t e m , f[Ć( t) ]Ć2 ( t) dt = F[Ć( t) ] = F( x) = f( x) dx. P R ZY K L A D . 1 1 1 x=3t c o s xdx = = ( c o s 3 t) 3 dt = 3 c o s tdt = 3 s in t+C = 3 s in x+C dx=3dt 3 3 3 1 x=3t x=t 3 Zwykle z a m ia s t p is z e m y . 1 dx=3dt dx=dt dx=3dt 3 P R ZY K L A D . 1 1 1 x+7=t 5 s in x+7 dx = = ( s in t) 5 dt = -5 c o s t+C = -5 c o s x+7 +C 1 dx=dt dx=5dt 5 5 5 P OD S TA W OW E W ZOR Y ( c z e s c d r u g a ) . Ca lko wa n ie o d n o s i s ie d o t yc h p r z e d z ia lo w, w kt o r yc h fu n kc je p o d c a lko we s a o kr e s lo n e . g2 ( x) dx = ln |g( x) | + C ( 1 1 ) g( x) ln xdx = x ln x - x + C ( 1 2 ) t g xdx = - ln | c o s x| + C ( 1 3 ) c t g xdx = ln | s in x| + C ( 1 4 ) " a r c s in xdx = x a r c s in x + 1 - x2 + C ( 1 5 ) 1 a r c t g xdx = xa r c t g x - ln ( 1 + x2) + C ( 1 6 ) 2 dx x = a r c s in + C ( 1 7 ) " q q - x2 dx = ln |x + q + x2| + C ( 1 8 ) q + x2 1 1 x q - x2dx = x q - x2 + q a r c s in + C ( 1 9 ) " 2 2 q 1 1 q + x2dx = x q + x2 + q ln |x + q + x2| + C ( 2 0 ) 2 2 1 1 2 s in xdx = x - s in 2 x + C ( 2 1 ) 2 4 1 1 2 c o s xdx = x + s in 2 x + C ( 2 2 ) 2 4 W ZOR Y R E K U R E N CY JN E : dx n n Ca lki In = , Jn = s in xdx, Kn = c o s xdx p o t r a fi m y o b lic z yc d la (1+x2)n n = 1 o r a z d la n = 0 . D la n e" 2 s t o s u je m y wz o r y: 1 x 2 n - 3 In = + In-1 n-1 2 n - 2 ( 1 + x2) 2 n - 2 1 n - 1 n-1 Jn = - c o s x s in x + Jn-2 n n 1 n - 1 n-1 Kn = s in x c o s x + Kn-2 n n