J jaclyncool7 New member Joined Jun 11, 2010 Messages 3 Jun 11, 2010 #1 What is the length of the curve with parametric equations x= (t+4)^2, y=4(t+4)^2 between the points corresponding to t=4 and t=7?
What is the length of the curve with parametric equations x= (t+4)^2, y=4(t+4)^2 between the points corresponding to t=4 and t=7?
G galactus Super Moderator Staff member Joined Sep 28, 2005 Messages 7,203 Jun 11, 2010 #2 Use the arc length formula: \(\displaystyle \int_{a}^{b}\sqrt{\left(\frac{dx}{dt}\right)^{2}+\left(\frac{dy}{dt}\right)^{2}}dt\) Find the derivative of x, square it. Find the derivative of y, square it. Plug it all in and integrate. You get: \(\displaystyle \int_{4}^{7}\sqrt{68(t+4)^{2}}dt\) Now, finish?.
Use the arc length formula: \(\displaystyle \int_{a}^{b}\sqrt{\left(\frac{dx}{dt}\right)^{2}+\left(\frac{dy}{dt}\right)^{2}}dt\) Find the derivative of x, square it. Find the derivative of y, square it. Plug it all in and integrate. You get: \(\displaystyle \int_{4}^{7}\sqrt{68(t+4)^{2}}dt\) Now, finish?.