So we just have to figure out when does v of t equal zero. So let's just say two sine of e to the t over four plus one is equal to zero, and there's multiple ways you can solve this, but because we're allowed to use a calculator, we might as well do that. So we hit Math, and then we hit B right over there. I'll just hit Enter. Equation Solver. So I could just say, look, the left side of my equation is two sine of, we are going to go e to the, I'll just use x as what I'm solving for because it's easier to type in in the calculator, and close that parentheses, plus one. The right-hand side is equal to zero, and now I just have to give an initial guess, and I'll just go right in between that interval between t equals zero and t equals six.