Find the equation of the line tangent to f(x)=3x^2-2x-1 at the point where x=2
the slope of the tangent line at any point (x,f(x)) is 6x-2
f(2) = 7
So, at (2,7) the slope is 10
now you have a point and a slope, so the tangent line is
y-7 = 10(x-2)