Question

need help :/

Answer 1

with ?

Answer 2

all xD

Answer 3

lol sorry

Answer 4

not as sry as I am xD

Answer 5

thats hard i wish i could help

Answer 6

as for plotting the graph, i have a program that'll do that for me, but for number 4 does the question mean when it says to find the location of each of its zeros?

Answer 7

What grade are you in?

Answer 8

it's ok, thx for checking the question out :)

Answer 9

im in first yr university >_<

Answer 10

your welcome sweety

Answer 11

Oh.... well good luck man! I hope you get it all figured out!

Answer 12

im assuming that by each of its zeros, it is reffering to the graph's x-axis intercepts or maybe its turning points

Answer 13

https://www.google.com/search?q=4.+For+the+function+f(x)+%3D+x+-+11+sin+(x%2F2+%2B+10)%2C+plot+its+graph+to+determine+the+approximate+location+of+each+of+its+zeros.+Then+find+each+of+the+zeros+by+numerically+solving+the+appropriate+equation.&oq=4.+For+the+function+f(x)+%3D+x+-+11+sin+(x%2F2+%2B+10)%2C+plot+its+graph+to+determine+the+approximate+location+of+each+of+its+zeros.+Then+find+each+of+the+zeros+by+numerically+solving+the+appropriate+equation.&aqs=chrome..69i57.96043j0j7&sourceid=chrome&espv=210&es_sm=93&ie=UTF-8

Answer 14

Yes, each of its zeros refers to the points where the graph intersects with the x-axis. The function will be zero at those points and therefore those x values are the roots of the equation.

Answer 15

ok so now im trying to solve the equation now,
f(x) = x - 11sin(x/2 + 10)
0 = x - 11sin(x/2 + 10)
x/11 = sin(x/2 + 10)
and now im assuming there is a trig identity I can use to break up sin(a + b)

Answer 16

The general shape of the graph can be guessed. The sine function has max/min values of +/- 1. And multiplying it by (-11) will have values in the range -/+ 11. And if y = x is plotted it will be a 45 degree straight line. So from this straight line plot you keep adding and subtracting 11 in a sine like manner and you are going to see a sine line function over the y=x line.

Answer 17

sin(A+B) = sinA.cosB + cosAsinB

Answer 18

ok thx, luckily the plotting isnt going to be a problem cause my teacher said that I dont need to plot the graph, there is a program that will plot the graph for me as long as i have its equation

Answer 19

so its just to solve the equation now, and when i use the program, ill be able to see where the zeros in the graph are

Answer 20

It has 5 zeros.
But the way to solve it is not coming to me yet.

Answer 21

i was never good with trigs lol thx for the identity :) i am trying to use it now

Answer 22

I am thinking ou may have to approximate the solution using Newton-Raphson method or something similar.

Answer 23

I will be very impressed if someone solves this equation directly.

Answer 24

hmm, ive heard of that, how does the method go again?

Answer 25

You start with a guess as to where the root may be and then you iterate repeatedly for better and better approximation:
http://en.wikipedia.org/wiki/Newton%27s_method

Answer 26

oh yea, and i think in this exercise everything is supposed to be approximated, so i think ur right

Answer 27

Based on the graph it looks like this equation has five roots. So it will be quite a bit of work to find all of them by numerical analysis.

Answer 28

would you think by plugging in different values of x into the equation and choosing the ones that give the y values closest to 0, is what I am supposed to do?

Answer 29

like wat we did for number 3?

Answer 30

i will be right back, im goign to use the bathroom quick

Answer 31

This is a bit different in that they ask you to first plot the graph and get the approximate root locations from the graph. You can get only so much accurate reading from a graph. Then you take each root plug it into the equation and see if it goes to zero. If not find a better and better successive approximations.
I like to take the midpoint each time. Let us say the graph shows there is a root between 5 and 10. I like to take the midpoint 7.5. Does the function change sign between 5 and 7.5 or 7.5 and 10? That is where the root is. Let us say 5 and 7.5. Then the midpoint is 6.25. Does it change sign between 5 and 6.25 or 6.25 and 7.5, etc.
And with each successive iteration you will get closer and closer to the root. Of course you will have to stop after so many decimals or else it will keep going forever.

Answer 32

From the graph I am getting these 5 points for x: -10.88, -9.53, -0.97, 6.37, 9.38

Answer 33

sry i took so long, im back