n! = 1 · . . . · n n 4 ! = 1 · 2 · 3 · 4 = 24 n! 0! = 1 ¡n¢ j = n! j!(n − j)! 0≤j≤n ¡ 5¢ 2 n ¡n¢ n! n j ¡n¢ Cnj j 5! 2!3 ! = 10 = ¡n¢ n! j j n ak + ak+ 1 n P + . . . + an j=k j a 1 + a 2 + . . . + an = n P aj = j=1 n P k=1 ak = n+ P2 at−2 t=3 (a + b)2 = a2 + 2ab + b2 (a + b)n = n µ ¶ X n j n−j a b j j=0 a0 = 1 a n − bn = (a − b)(an−1 + an−2 b + . . . + abn−2 + bn−1 ) n X an−j bj−1 = (a − b) j=1 aj j=1 a 1≤j≤n n aj = a + (j − 1)d d µ ¶ n X n−1 aj = n a + Sn = ·d 2 j=1 a=1 1≤j≤n n d=1 n X n−1 n(n + 1) j = n(1 + · 1) = = 2 2 j=1 j=1 aj = j a µ ¶ n+1 2 1≤j≤n n aj = aq j−1 q 6= 1 Sn = n X aq j−1 = a · j=1 n+1 ∈ A 1 − qn 1−q 1 n ∈ A A A 1≤j≤n aj = a + (j − 1)d . n X µ ¶ n−1 aj = n a + ·d 2 j=1 n=1 n+1 n n A n a n P j=1 n+1 X j=1 aj ¡ aj = n a + n−1 2 ·d ¢ n X ¶ µ n−1 d aj = (a + nd) + n a + 2 j=1 ³ ´ n(n − 1) n = (n + 1)a + n + d = (n + 1)a + (n + 1) d 2 2 ³ n ´ = (n + 1) a + d 2 = an+1 + n n 2x + 3y + z = 6 x − 2y + z = 0 x+y+z =3 2x + 3y + z = 6 −7y + z = −6 −y + z = 0 y=z=1 y=z x=1 c c> 0 c< 0 n √ n a> √ n b an > b n a> b a+c> b+c ac > bc ac < bc a> b> 0 ∗ ∗ ∗ • • −a < x < a x0 − a < x < x 0 + a |x| < a • |x − x0 | < a • a, b |a + b| ≤ |a| + |b| b = −y, a = x + y |x + y| ≥ . a, b |x| − |y| • , |x − 3| + |x + 1| < 9 . (x − 1)(x − 3)2 (x − 6)3 <0 (x + 4)(x + 5 )2 • y = ax + b α ta n α a x x (x0 , y0 ) y − y0 = a(x − x0 ) x0 6= x1 (x1 , y1 ) • a y = a(x − x0 ) + y0 (x0 , y0 ) y − y0 = • y1 − y0 (x − x0 ) x 1 − x0 y1 − y0 x1 − x 0 x y = a 2 x + b2 1 a1 = − a2 (x0 , y0 ) (x − x0 )2 + (y − y0 )2 = r2 y = a1 x + b1 a2 6= 0 r a1 6= 0 • • a 6= 1 a>0 x, y ax+y = ax ay a−x = 1 ax (ax )y = axy lo g a x a x>0 lo g a x x=a y lo g a x = y x, y > 0 lo g a (xy) = lo g a x + lo g a y µ ¶ 1 lo g a = − lo g a x x lo g a xy = y lo g a x a, b > 0 lo g a x = lo g a b · lo g b x. α ' 6A $ 1 - _ AB < AO &% O 0, =α B 360◦ β 1 α B =α 2π 1 β· π π π π , , , , π 6 4 3 2 sin(x + 2π) = sin x c o s(x + 2π) = c o s x tan(x + π) = tan x 2π 360 a sin(−x) = − sin x cos(−x) = cos x tan(−x) = − tan x π 2 π ) = cos x 2 1 π tan(x + ) = − 2 tan x sin(x + sin2 x + cos2 x = 1 1 −1 tan2 x = cos2 x sin 2x = 2 sin x cos x cos 2x = cos2 x − sin2 x x−y x+y cos 2 2 x+y x−y sin cos x − cos y = −2 sin 2 2 sin x − sin y = 2 sin π−t t + 2π y = arcsin x t sin y = x cos y = x tan y = x √ cos(arcsin x) = 1 − x2 arcsin x sin t = a t 0≤y≤π π π − <y< 2 2 − π π ≤y≤ 2 2 y y y = arccos x y y = arctan x 1 x cos(arcsin x) Z x Z 1 Z Z cos(arcsin x) n p(x) = a0 + a1 x + . . . + an xn = n X aj x j j=0 an = 1 n an 6= 0 aj d e g(p) = n n p(x) p(x) = 0 n ax2 + bx + c ∆ = b2 − 4ac √ −b ± ∆ 2a −b 2a q, r n = qm + r ∆>0 • ∆=0 • ∆<0 • 0<m<n • r<m 0 < m < n m g(x) f (x) n r(x) q(x) f (x) = q(x)g(x) + r(x) d e g(r) < m x3 − x2 + x − 1 x3 + x2 −2x2 + x − 1 −2x2 − 2x 3x − 1 3x + 3 −4 f (x) = x3 − x2 + x − 1 : x+1 = r(x) = −4 r(x) g(x) = x + 1 x2 − 2x + 3 q(x) = x2 − 2x + 3 • m=kl • m>1 k ,l > 1 p(x) = f (x) · g(x) • p(x) deg(g) ≥ 1 deg(f ) ≥ 1 1 2 2 2 x − 1 = (x − 1)(x + 1) 2 x +1 x −1 ∗ x +1 ∗ 2 x + 1 = f (x) · g(x) deg(f ) ≥ 1 deg(f ) = deg(g) = 1 − ab f (x) a 6= 0 ∗ 2 deg(g) ≥ 1 f (x) = ax + b 2 x2 + 1 x +1 p(x) p(x) = f1 (x) · · · fk (x) fj λ1 · · · λk = 1 n 6= 0 m, n λj N = {1, 2, . . .} N Z = {0, ±1, ±2, . . .} m n Z Q R A A B A x B A x x∈A x x∈ / A A⊂B A 6= B A⊂ 6= B A⊂B A=B A⊆B {x: x} Q={x: A x {x∈A: {x ∈ Z : −1 ≤ x < 3} x {−1, 0, 1, 2} 9 } x }