y = f(f(t)).
3 ( ).
x = f (t) t, y = f(x) x = f (t). y = f( f (t)) t,
(f (f(t))) ' = f' (x)f ' (t). | (3) |
. x = f(t) D t. D x = f (t+D t)-f (t) x = f(t). D x D y = f(x+ D x)-f(x). y = f(x), D y (1):
D y =f' (x)D x + a (D x) D x,
limD x 0a (D x) = 0. D t ¹ 0, :
D y/ D t=f' (x)D x/ D t+ a (D x)D x/ D t.
x = f (t) t ,
limD t 0D x/ D t = f ' (t).
, x = f(t) , D x 0 Dt 0. , limD t 0a (D x) =0. , (3).
5. y', y = 5cos x.
y' = 5cos x (-sin x)ln 5=-5cos x sin x ln 5.
,
4 ( ).
y = f(x) ( ) x. , , x f'(x) ¹0. y = f(x) x = f- 1 (y), x = f- 1 (y)
(f- 1(y)) ' = 1 /f' (x).
. y = f(x) x, x = f-1(y), y = f(x).
D y¹ 0 y, D x - x = f-1(y).
D x/ D y = 1 / (D y/ D x).
D y 0 , D x 0,
limD y 0D x/ D y = 1 / (limD x 0D y/ D x).
, x'(y) = 1/y'(x).
. M f(x), (.22), f'(x) a, M, OX, (f-1(y))' y = f(x) b OY. a+ b=p/2, : tgb = 1/tg a.
6. x'y, y = 2x3+3x5+x y' = 6x2+15x4+1, x'y = 1/y'x = 1/(6x2+15x4+1).
, . , , " " .1 .. , .. , .. .
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- (u a(x))' = a u a-1(x) u '(x), ,
(1 /u (x)) ' = -u' (x) /u 2(x), () ' = u' (x) / 2 ;
2. (loga u (x))' = (u'(x)logae)/u(x) 0<a¹1, u(x)>0, , (ln u (x))' = u'(x)/ u (x);
3. (a u (x))' = a u (x)ln a u '(x) 0<a¹1, , (e u (x))' = u'(x)e u (x);
4. (sin u (x))' = cos u (x) u '(x);
5. (cos u (x))' = -sin u (x) u '(x);
6. (tg u (x))' = u '(x)/cos2 u (x) x¹ p/2+p n, n=0,+-1,...;
7. (ctg u (x))' = - u '(x)/sin2 u (x) x¹ p n, n=0,+-1,...;
8. (arcsin u (x))' = u '(x)/ , -1< u (x)<1;
9. (arccos u (x))' = - u '(x)/ , -1< u (x)<1;
10. (arctg u (x))' = u '(x)/(1+ u 2(x));
11. (arcctg u (x))' = - u '(x)/(1+ u 2(x)).
:
sh x = (1 / 2)(ex-e-x)- ;
ch x = (1 / 2)(ex+ex)- ;
th x = sh x/ ch x - ;
cth x = ch x/ sh x - .
.
- (sh x) ' = ch x;
- (ch x) ' = sh x;
- (th x) ' = 1 / ch2 x;
- (cth x) ' = -1 / sh2 x.
7. y',
1. y(x) = x3arcsin x.
2. y(x) = ln sin (x2+1).
y' = (2 x cos(x 2+1)) / sin(x 2+1) = 2 x ctg (x 2+1)
. , .