Determine the equation of both lines that are tangent to the graph of y=x^2 +4 and pass through the point (1,-2)
So would I simply use the y=mx+b form, m=2, y= -2, and x = 1?
point of tangency on the curve is $\displaystyle (x,x^2+4)
$
each tangent line passes thru the point $\displaystyle (1, -2)$
remember how to find the slope between two points?
... also, note that the slope of both tangent lines is y' = 2x
I'll let you take it from here.