We're told the function f is twice differentiable with f of two equals one, f prime of two is equal to four, and f prime prime of two is equal to three. What is the value of the approximation of f of 1.9 using the line tangent to the graph of f at x equals two? So pause this video and see if you can figure this out. This is an actual question from a past AP calculus exam. All right, now let's do this together. And if I was actually doing this on exam, I would just cut to the chase and I would figure out the equation of the tangent line at x equals two, go through the point two comma one, and then I would figure out, okay, when x is equal to 1.9, what is the value of y? And that would be my approximation.