Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Help me with sine questions

  1. Nov 6, 2006 #1
    Help me with sine questions.. URGENT

    Hi I am trying to solve these and i cant understand them .. please help me

    Q1:: Write an equation for a sine curve that has the following characteristics: - amplitude of 5, -max of 7, min of -3 and one cycle starts at pi/8 and this cycle ends at 9 pi/8



    Q2:the number of hrs of daylight for a particular area is related to the day of the year as follows: D=12 +2.5 sin[2pi/365(t-81)], where D is the number of hours of daylight and t is the day of the year, with t= 1 representing january 1st. find the amplitude, period , phase shift and vertical shift for the equation.
     
  2. jcsd
  3. Nov 7, 2006 #2

    HallsofIvy

    User Avatar
    Staff Emeritus
    Science Advisor

    Any "sin curve" can be written y= A sin(bx+ c)+ D. Since the largest possible value of sine is 1 and the smallest is -1, that will have a largest value of A+ D and smallest of -A+ D. One cycle of sin(x) starts at x= 0 and ends at x= 2[itex]\pi[/itex]. One cycle of sin(bx+ c), then, starts when bx+ c= 0 and ends when bx+ c= 2[itex]\pi[/itex]. Use the information given to find A, b, c, and D.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Help me with sine questions
  1. 3 questions, help me (Replies: 2)

Loading...