回答:
F'(x)的== -
说明:
为了找到f(x)的导数,我们需要使用链规则。
让
和
=
=
=-
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。
你如何使用链规则区分f(x)= sqrt(ln(x ^ 2 + 3)。
F'(X)=(X(LN(X ^ 2 + 3))^( - 1/2))/(X ^ 2 + 3)= X /((X ^ 2 + 3)(LN(X ^ 2 + 3))^(1/2))= x /((x ^ 2 + 3)sqrt(ln(x ^ 2 + 3)))我们给出:y =(ln(x ^ 2 + 3) )^(1/2)y'= 1/2 *(ln(x ^ 2 + 3))^(1 / 2-1)* d / dx [ln(x ^ 2 + 3)] y'=( ln(x ^ 2 + 3))^( - 1/2)/ 2 * d / dx [ln(x ^ 2 + 3)] d / dx [ln(x ^ 2 + 3)] =(d / dx [x ^ 2 + 3])/(x ^ 2 + 3)d / dx [x ^ 2 + 3] = 2x y'=(ln(x ^ 2 + 3))^( - 1/2)/ 2 *(2×)/(X ^ 2 + 3)=(X(LN(X ^ 2 + 3))^( - 1/2))/(X ^ 2 + 3)= X /((X ^ 2 + 3)(LN(X ^ 2 + 3))^(1/2))= X /((X ^ 2 + 3)SQRT(LN(X ^ 2 + 3)))
你如何使用链规则区分f(x)= sin(sqrt(arccosx ^ 2))?
- (xcos(sqrt(arccosx ^ 2)))/(sqrt(1-x ^ 4)* sqrt(arccosx ^ 2))为区分f(x),我们必须将其分解为函数,然后使用链规则对其进行区分:设:u(x)= arccosx ^ 2 g(x)= sqrt(x)然后,f(x)= sin(x)使用链规则的复合函数的导数如下所示:颜色(蓝色)(( f(g(u(x))))'= f'(g(u(x)))* g'(u(x))* u'(x))让我们找到上述每个函数的导数:u '(x)= - 1 / sqrt(1-(x ^ 2)^ 2)* 2x颜色(蓝色)(u'(x)= - 1 /(sqrt(1-x ^ 4))* 2x g' (x)= 1 /(2sqrt(x))用u(x)代x,我们得到:颜色(蓝色)(g'(u(x))= 1 /(2sqrt(arccosx ^ 2))f'(x )= cos(x)用g代替x(u(x))我们必须找到颜色(红色)(g(u(x))):颜色(红色)(g(u(x))= sqrt(arccosx) ^ 2))所以,f'(g(u(x)))= cos(g(u(x))颜色(蓝色)(f'(g(u(x)))= cos(sqcos(arccosx ^) 2))用上面的链规则代替计算的导数我们得到:颜色(蓝色)((f(g(u(x))))'= f'(g(u