Engineering Board Exam Reviewer · Tangent and Normal Lines · easy

Find the equation of the tangent line to y=x2 at the point (3,9).

  1. y=6x+9
  2. y=3x
  3. y=6x-9
  4. y=9x-18

Answer

C. y=6x-9

Solution

y'=2x=6 at x=3. The line is y-9=6(x-3) y=6x-9.

More Tangent and Normal Lines questions

  1. Find the slope of the tangent line to y=x3-2x at x=2.
  2. Find the area of the triangle formed by the coordinate axes and the tangent line to y= 1x at x=2.
  3. Find the equation of the tangent line to x2+xy+y2=7 at the point (2,1).
  4. Find the points on y=x3-3x+1 where the tangent line is horizontal.
  5. Find the angle of inclination (in degrees) of the tangent line to y=x2 at x=1.
  6. At what point on the curve y=x2-4x+5 is the tangent line parallel to the line y=2x+1?
  7. Find the equation of the normal line to y= x at x=4.

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