Question

Determine the equations of both lines that are tangent to the graph of f(x)=x^2 and pass through point (1,-3).

Answer 1

I got the slope: m=2

Answer 2

(1, -3) is not a point on the graph..

Answer 3

tangent to the graph of f(x)=x^2
means one point on the line is also on this curve, at (x, x^2)
because y= x^2

the slope of the tangent line will be 2x (take the derivative of x^2)
use the point slope formula through point (1,-3)
y - (-3) = m ( x - 1)
slope is 2x, y is x^2
x^2 +3 = 2x(x-1)
simplify and solve for x (2 values)

now you have two points: (1,-3) and (x,x^2) (evaluated at the correct x)
from which you can find an equation of the tangent line

Answer 4

aahh.. got it thanks a lot!!!(^_^)