See worked example of how to find the appropriate expression to use in order to solve word problems using definite integrals. Practice this lesson yourself on KhanAcademy.org right now: https://www.khanacademy.org/math/ap-calculus-ab/ab-applications-definite-integrals/ab-applying-def-integrals/e/analyzing-problems-involving-definite-integrals?utm_source=YT&utm_medium=Desc&utm_campaign=APCalculusAB Watch the next lesson: https://www.khanacademy.org/math/ap-calculus-ab/ab-applications-definite-integrals/ab-applying-def-integrals/v/area-under-rate-function-example?utm_source=YT&utm_medium=Desc&utm_campaign=APCalculusAB Missed the previous lesson? https://www.khanacademy.org/math/ap-calculus-ab/ab-applications-definite-integrals/ab-applying-def-integrals/v/interpreting-definite-integrals-in-context?utm_source=YT&utm_medium=Desc&utm_campaign=APCalculusAB AP Calculus AB on Khan Academy: Bill Scott uses Khan Academy to teach AP Calculus at Phillips Academy in Andover, Massachusetts, and heÕs part of the teaching team that helped develop Khan AcademyÕs AP lessons. Phillips Academy was one of the first schools to teach AP nearly 60 years ago. ... https://www.youtube.com/watch?v=U4dtruMdQ7Y Note: All Khan Academy content is available for free at (www.khanacademy.org)

Apsidal Precession (Perihelion Precession). Created by Sal Khan. Watch the next lesson: https://www.khanacademy.org/science/cosmology-and-astronomy/life-earth-universe/history-life-earth-tutorial/v/earth-formation?utm_source=YT&utm_medium=Desc&utm_campaign=cosmologystronomy Missed the previous lesson? https://www.khanacademy.org/science/cosmology-and-astronomy/earth-history-topic/earth-title-topic/v/what-causes-precession-and-other-orbital-changes?utm_source=YT&utm_medium=Desc&utm_campaign=cosmologystronomy Cosmology & Astronomy on Khan Academy: The Earth is huge, but it is tiny compared to the Sun (which is super huge). But the Sun is tiny compared to the solar system which is tiny compared to the distance to the next star. Oh, did we mention that there are over 100 billion stars in our galaxy (which is about 100,000 light years in diameter) which is one of hundreds of billions of galaxies in just the observable universe (which might be infinite for all we know). Don't feel small. We find it liberating. Your everyday human stresses are nothing compared to this enormity that we are a part of. Enjoy the fact that we get to be part of this vastness! About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. ... https://www.youtube.com/watch?v=m6lMGoZTJnc Note: All Khan Academy content is available for free at (www.khanacademy.org)