The equation of tangent to the curve y (1 + x2) = 2 – x, where it crosses x-axis is:
Given the equation of the curve is
y (1 + x2) = 2 – x
Differentiating on both sides with respect to x, we get
Applying the power rule we get
We know derivative of a constant is 0, so above equation becomes
Applying the power rule we get
As the given curve passes through the x-axis, i.e., y=0,
So the equation on given curve becomes,
y(1+x2)=2-x
⇒ 0(1+x2)=2-x
⇒ 0=2-x
⇒ x=2
So the given curve passes through the point (2,0)
So the equation (i) at point (2,0) is,
Hence, the slope of tangent to the curve is
Therefore, the equation of tangent of the curve passing through (2,0) is given by
⇒ 5y=-x+2
⇒ x+5y=2
So the equation of tangent to the curve y (1 + x2) = 2 – x, where it crosses x-axis is x+5y=2.
Therefore the correct option is option A.