回答:
要么
说明:
我们有:
要么
什么是(sqrt(5+)sqrt(3))/(sqrt(3+)sqrt(3+)sqrt(5)) - (sqrt(5-)sqrt(3))/(sqrt(3+)sqrt (3-)SQRT(5))?
2/7我们采取,A =(sqrt5 + sqrt3)/(sqrt3 + sqrt3 + sqrt5) - (sqrt5-sqrt3)/(sqrt3 + sqrt3-sqrt5)=(sqrt5 + sqrt3)/(2sqrt3 + sqrt5) - (sqrt5 -sqrt3)/(2sqrt3-sqrt5)=(sqrt5 + sqrt3)/(2sqrt3 + sqrt5) - (sqrt5-sqrt3)/(2sqrt3-sqrt5)=((sqrt5 + sqrt3)(2sqrt3-sqrt5) - (sqrt5-sqrt3) )(2sqrt3 + sqrt5))/((2sqrt3 + sqrt5)(2sqrt3-sqrt5)=((2sqrt15-5 + 2 * 3-sqrt15) - (2sqrt15 + 5-2 * 3-sqrt15))/((2sqrt3) ^ 2-(sqrt5)^ 2)=(取消(2sqrt15)-5 + 2 * 3cancel(-sqrt15) - 取消(2sqrt15)-5 + 2 * 3 +取消(sqrt15))/(12-5)=( -10 + 12)/ 7 = 2/7请注意,如果在分母中(sqrt3 + sqrt(3 + sqrt5))和(sqrt3 + sqrt(3-sqrt5))那么答案将会改变。
在x = -2时,f(x)= 14x ^ 3-4x ^ 2e ^(3x)的切线方程是多少?
找到f(-2)和f'( - 2)然后使用切线公式。切线方程为:y = 167.56x + 223,21 f(x)= 14x ^ 3-4x ^ 2e ^(3x)求导数函数:f'(x)=(14x ^ 3)' - ( 4x ^ 2e ^(3x))'f'(x)= 14(x ^ 3)' - 4 [(x ^ 2)'e ^(3x)+ 4x ^ 2(e ^(3x))'] f '(x)= 14 * 3x ^ 2-4 [2xe ^(3x)+ 4x ^ 2 * e ^(3x)*(3x)'] f'(x)= 42x ^ 2-4 [2xe ^(3x )+ 4x ^ 2 * e ^(3x)* 3] f'(x)= 42x ^ 2-4 [2xe ^(3x)+ 12x ^ 2 * e ^(3x)] f'(x)= 42x ^ 2-8xe ^(3x)[1 + 6x]求f(-2)f(x)= 14x ^ 3-4x ^ 2e ^(3x)f(-2)= 14 *( - 2)^ 3-4 *( - 2)^ 2e ^(3 *( - 2))f(-2)= 32e ^( - 6)-112 f(-2)= 111.92和f'( - 2)f'(x)= 42x ^ 2-8xe ^(3x)[1 + 6x] f'( - 2)= 42 *( - 2)^ 2-8 *( - 2)e ^(3 *
在x = -1时,f(x)=(x-2)/(x ^ 2-4)的切线方程是多少?
Y = -xf(x)=(x-2)/((x-2)(x + 2))(a ^ 2-b ^ 2 =(a + b)(ab))f(x)= 1 /(x + 2)=(x + 2)^ - 1 f'(x)= - (x + 2)^ - 2 f'( - 1)= - ( - 1 + 2)^ - 2 = - ( 1)^ - 2 = -1 f(-1)=( - 1 + 2)^ - 1 = 1 ^ -1 = 1 y-y_0 = m(x-x_0)y-1 = -1(x + 1 )y-1 = -x-1 y = -x