completely stuck here:
1. find the value of k for which y = 3x+1 is a tangent to the curve
x^2 + y^2 = k
2. find the range of values of k for which y=x-3 meets x^2-3y^2=k in two distinct points.
and i went wrong in this question, no idea where though
find the number of points of intersection
y= x/4 + 1
y^2 = x
i multiplied by 4 to get rid of the fraction. do i square root x ??