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skullofreak Group TitleBest ResponseYou've already chosen the best response.0
how do I write the equation of the graph?
 9 months ago

alffer1 Group TitleBest ResponseYou've already chosen the best response.0
Tell me what the graph of y = cos x looks like.
 9 months ago

skullofreak Group TitleBest ResponseYou've already chosen the best response.0
its (0,1) (pi,1) (2pi,1) (3pi,1) etc
 9 months ago

skullofreak Group TitleBest ResponseYou've already chosen the best response.0
but with the dots in um the up and down motions (from half of 0 and pi , pi and 2pi,
 9 months ago

alffer1 Group TitleBest ResponseYou've already chosen the best response.0
So what is the difference between this one and cosx?
 9 months ago

skullofreak Group TitleBest ResponseYou've already chosen the best response.0
its sin ? and the graph is given but I don't know how to get an equation
 9 months ago

skullofreak Group TitleBest ResponseYou've already chosen the best response.0
nvm its cos
 9 months ago

ranga Group TitleBest ResponseYou've already chosen the best response.1
The sine function is zero when x = 0. A cosine function is 1 when x = 0. So we need to choose the acos(bx) here. a is the amplitude. Amplitude is how much above or how much below the mean line (which is x axis here) the curve swings. Could you figure out the amplitude from the diagram?
 9 months ago

skullofreak Group TitleBest ResponseYou've already chosen the best response.0
so y = 3cos.. bx
 9 months ago

ranga Group TitleBest ResponseYou've already chosen the best response.1
Yes. a = 3. So the equation is y = 3cos(bx). We still need to figure out b. The period of a cosine or a sine function is how long before the curve repeats itself. Could you look at two successive peaks in the diagram and figure out after how much x the function repeats itself?
 9 months ago

skullofreak Group TitleBest ResponseYou've already chosen the best response.0
every 3pi?
 9 months ago

skullofreak Group TitleBest ResponseYou've already chosen the best response.0
or every 6pi/2?
 9 months ago

ranga Group TitleBest ResponseYou've already chosen the best response.1
No. The curve attains a peak at x = 0. The next peak occurs at x = 6pi. The period is how much x has passed before the curve starts to repeat itself. So what is the x distance between peaktopeak?
 9 months ago

ranga Group TitleBest ResponseYou've already chosen the best response.1
No. At x = 0, first peak. At x = 6pi the next peak. The difference in x is: 6pi  0 = 6pi. Every 6pi the curve repeats itself. You can take the distance between two successive low points also and it will still be 6pi. So the period of this curve is 6pi.
 9 months ago

skullofreak Group TitleBest ResponseYou've already chosen the best response.0
y=3cos (6pi)x ?
 9 months ago

ranga Group TitleBest ResponseYou've already chosen the best response.1
The formula for the period of cos(bx) is: Period = 2pi / b Looking at the graph we found the period to be 6pi. Plug that into the formula: 6pi = 2pi / b Find b.
 9 months ago

skullofreak Group TitleBest ResponseYou've already chosen the best response.0
2pi/6pi = pi/3pi
 9 months ago

ranga Group TitleBest ResponseYou've already chosen the best response.1
The pi will cancel out. so b = ?
 9 months ago

skullofreak Group TitleBest ResponseYou've already chosen the best response.0
yes sorry
 9 months ago

ranga Group TitleBest ResponseYou've already chosen the best response.1
Yes. Put them all together and the curve represented in the graph is: y = 3cos(1/3*x)
 9 months ago

skullofreak Group TitleBest ResponseYou've already chosen the best response.0
okay thank you!! a lot!
 9 months ago

ranga Group TitleBest ResponseYou've already chosen the best response.1
You are welcome.
 9 months ago
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