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sabika13
Group Title
Write an equation this is equivalent to f(x)=5sin(xpi/2)  8 using trig.function of x
 2 years ago
 2 years ago
sabika13 Group Title
Write an equation this is equivalent to f(x)=5sin(xpi/2)  8 using trig.function of x
 2 years ago
 2 years ago

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richyw Group TitleBest ResponseYou've already chosen the best response.0
ok so you have \[f(x)=5\sin\left(x\frac{\pi}{2}\right)8\] For now just focus on \[g(x)=\sin\left(x\frac{\pi}{2}\right)\] what does this do to the graph?
 2 years ago

richyw Group TitleBest ResponseYou've already chosen the best response.0
where \(x=\pi/2\), what is \[\sin\left(x\frac{\pi}{2}\right)\]also brb. just gotta hand in something quick...
 2 years ago

sabika13 Group TitleBest ResponseYou've already chosen the best response.0
okay.. will it be sin(xpi/2)=0??
 2 years ago

sabika13 Group TitleBest ResponseYou've already chosen the best response.0
i dont really understand the question itself
 2 years ago

richyw Group TitleBest ResponseYou've already chosen the best response.0
sorry open study died on me.
 2 years ago

richyw Group TitleBest ResponseYou've already chosen the best response.0
You are correct that \(g(\pi/2)=0\) You can repeat this with some other key xvalues \(x=\pi/2,\quad x=\pi ,\quad x=0 \) and find that what you get is \[\sin\left(x\frac{\pi}{2}\right)=\cos\pi\]
 2 years ago

richyw Group TitleBest ResponseYou've already chosen the best response.0
you will eventually just memorize these phase shifts, but if you ever forget on a test, you can always make a quick sketch using the method I explained. So now remember that we called \[g(x)=\sin\left(x\frac{\pi}{2}\right)=\cos x\] Going back to the original function you have \[f(x)=5\sin\left(x\frac{\pi}{2}\right)8\]\[f(x)=5g(x)8\]So the hard part is already done. The 8 is all by itself so it just shifts the up and down, and the 5 just makes the amplitude of the wave greater. All you have to do now is plug in the expression you worked out for g(x). \[f(x)=5(\cos x)8\]\[f(x)=5\cos x 8\]
 2 years ago

richyw Group TitleBest ResponseYou've already chosen the best response.0
Oops made a mistake, in the second last post. It should say : You are correct that \(g(π/2)=0\) You can repeat this with some other key xvalues \(x=π/2,\quad x=π,\quad x=0\) and find that what you get is \[\sin\left( x−\frac{\pi}{2}\right)=−\cos x\]
 2 years ago

sabika13 Group TitleBest ResponseYou've already chosen the best response.0
sorry i fell alseep _ .. accoriding the the cofunction identities isnt it : cosx=sin(pi/2x)? so using that you can get cosx=sin(xpi/2) (sorrydont understand)
 2 years ago
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