# Definition of the Tangent Line

### Topic Page

Definition of the Tangent Line### Questions

- What is a tangent line?
- What are common mistakes students make with tangent lines?
- How do I find the tangent line of a function?
- How do I find the tangent line of #y=x^2# at its vertex?
- How do I draw tangent lines?
- What is the tangent line of a parabola at its vertex?
- How can I tell if a line is tangent to a circle?
- What is a secant line?
- How do I find the secant line through two points?
- What is the formula for the slope of a secant line?
- Question #9a3da
- Why are the tangents for 90 and 270 degrees undefined?
- How do you find the equation of the tangent to the curve #y = 2 - sin^2 x# at the point where x = pi/6?
- Are there any numbers for which the expression #(8x^4+9)/(9x^2+18x)# undefined?
- Question #d8efe
- Question #d8ad1
- Find the equation of tangent parallel to the secant joining the points on the curve #y=x^2# at #x=-1# and #x=2#?
- Two tangents to the parabola #y=1-x^2# intersect at point #(2,0)#. Find the coordinates of points on parabola on which these are tangents?
- Find the condition under which the line #xcosalpha+ysinalpha=p# will be a tangent to the conic #3x^2+4y^2=5#?