Finding equation of both lines

[Meeker]

Homework Statement

Determine the equation of both lines that are tangent to the graph of y=x^2 +4 and pass through the point (1,-2)

Homework Equations

The Attempt at a Solution

The derivative/slope of the tangent is 2x. But I'm not too sure what to do with this.

 

[Dick]

Ok so let (x,y) be a point on your curve. That makes it (x,x^2+4), right? Now find the slope of the line between that point and (1,-2). That slope should be your 2x, also right? Now solve for x.

 

[Meeker]

Ok so let (x,y) be a point on your curve. That makes it (x,x^2+4), right? Now find the slope of the line between that point and (1,-2). That slope should be your 2x, also right? Now solve for x.

Alright. Once I find x, what do I do with it?.

Btw, the slope for that line is (x-1)/(x^2+6) rite?

 

[Dick]

Alright. Once I find x, what do I do with it?.

Btw, the slope for that line is (x-1)/(x^2+6) rite?

Slope is delta(y)/delta(x), isn't it? Once you find values for x, each one gives you a point on the curve that also goes through (1,-2). Use the points to find the line equations.