Q. Find the equation of the normal to the curve y=2x+1x−2 at the point where the curve cuts the x-axis.
Find x-intercept: First, we need to find the point where the curve cuts the x-axis. This happens when y=0.y=2x+1x−2=0To find the x-coordinate of this point, we set the numerator of the fraction to zero because a fraction is zero if and only if its numerator is zero.x−2=0x=2
Determine point coordinates: Now we have the x-coordinate of the point where the curve cuts the x-axis. The y-coordinate is already known to be 0 since it's on the x-axis. So the point is (2,0).
Calculate tangent slope: Next, we need to find the slope of the tangent to the curve at the point (2,0). To do this, we find the derivative of y with respect to x.y=2x+1x−2Using the quotient rule, the derivative y′ is:y′=(2x+1)2(2x+1)(1)−(x−2)(2)y′=(2x+1)22x+1−2x+4y′=(2x+1)25
Evaluate slope at x=2: Now we evaluate the derivative at the point x=2 to find the slope of the tangent.y′(2)=(2⋅2+1)25y′(2)=(4+1)25y′(2)=255y′(2)=51
Find normal slope: The slope of the normal is the negative reciprocal of the slope of the tangent. Since the slope of the tangent at x=2 is 51, the slope of the normal is −5.
Derive normal equation: Now we have the slope of the normal and a point through which it passes. We can use the point-slope form of the equation of a line to find the equation of the normal.The point-slope form is: y−y1=m(x−x1), where m is the slope and (x1,y1) is the point.Using the point (2,0) and the slope −5, the equation is:y−0=−5(x−2)y=−5x+10
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