Tangent equation of y = INX and X-axis phase point of curve

Tangent equation of y = INX and X-axis phase point of curve

Tangent equation of the intersection of y = INX and X axis
lnx=0
x=1
y=lnx
Let the tangent equation y = KX + B
y'=1/x=k=1
b=0-1=-1
Tangent equation y = X-1

It is known that the tangent equation of function f (x) = 13x3 − bx2 + CX + D at point (0, f (0)) is y = 2

It is known that the function f (x) is a decreasing function on R if f (X & # 178; + 2) < f (3x)
Find the value range of X

The function f (x) is a decreasing function on R if f (X & # 178; + 2) < f (3x)
Then x & # 178; + 2 > 3x
x² -3x + 2>0
(x - 1)(x - 2)>0
x> 2 or X

The tangent equation of the function f (x) = ln x at (1,0) is

The tangent equation of function f (x) = ln x at (1,0) is y = X-1