limit as x approaches pi of cos(x)

解答

x \to π lim (cos (x))

- 1

求解步骤

x \to π lim (cos (x))

代入值

x = π

= cos (π)

使用以下普通恒等式:

cos (π) = (- 1)

cos (x)

周期表（周期为

2 πn

）：

x 0 \frac{π}{6} \frac{π}{4} \frac{π}{3} \frac{π}{2} \frac{2 π}{3} \frac{3 π}{4} \frac{5 π}{6} cos (x) 1 \frac{3}{2} \frac{2}{2} \frac{1}{2} 0 - \frac{1}{2} - \frac{2}{2} - \frac{3}{2} x π \frac{7 π}{6} \frac{5 π}{4} \frac{4 π}{3} \frac{3 π}{2} \frac{5 π}{3} \frac{7 π}{4} \frac{11 π}{6} cos (x) - 1 - \frac{3}{2} - \frac{2}{2} - \frac{1}{2} 0 \frac{1}{2} \frac{2}{2} \frac{3}{2}

= - 1

d er i v a t i v e \frac{2}{( x + 2 ) ^{2}}

\int (\frac{4}{x} + 2 e^{x} - sin (x)) d x

t an g e n t y = 2 x^{3} - 3 x + 1, (1, 0)

d er i v a t i v e x^{2} + 6 x + 9

d er i v a t i v e 4 ln (9 - 5 x^{2})